Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: TheBoy on 16 October 2011, 14:43:38
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This is starting to do my head in...
Some of the details may be a bit sketchy, as a lot has happened with this car over the past 2 or 3 months, and old age and 2 similar looking Omegas confuses simple country folk like me.
Nail the brakes, it seems fine, or at least as fine as the Heinz 57 tyres allow. Its medium braking, moreso at 50+, the car noticeably pulls right, requiring steering left enough that releasing the brakes causes the car to snap left.
When not on the brakes, car drives pretty straight, though does tend to tramline as its running quite a lot of front camber.
Swapped tyres front to back (which cured my chronic understeer in right hand corners, but introduced an interesting oversteer issue on the same bends ;D).
Rebled brakes
Filed down front pads in cause on contamination
Its had different springs and shocks, no change
WIM'd
Different wheels and tyres
There is some debate if it was pulling left at some point, rather than right....
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what state are the wishbones in?
brake calipers moving freely?
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This car already has polys, yes?
Has the fluid been changed or just bled?
Idler in good condition?
Finally... Is the pitman arm on the steering box pointing straight down the car in the straight ahead position?
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Sticky cliper has to be the favourite imo. ;)
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IMHO, you've either got very uneven braking side-to-side or something in the suspension is moving under braking. Wishbones would be the first port of call, IMHO, followed by the track rods and idler.
Could always be a problem at the back, of course.
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I think you already checked front setup and geometry..
if the tire pressures and tire shapes are ok, the only option is braking forces are not equal
which I also have and measured during mot :-\
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also a slightly buckeld wheel can change things drastically..
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Is this the one that's just been mot'd? If so, what were the brake roller readings as it's an easy rule out if the efficiency is basically the same across an axle. Just ensure that there is no excess on one side or the other. If you don't have a note of readings perhaps your friendly (?) testing station may assist. ;)
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Wishbones are original, but have been polyed at the front, and MDTM pressed in some rears.
No play felt in either track rods, or in idler. Will check pitman arm more precisely, but looked pretty straight earlier. Slight play in OSF wheel bearing.
No play found in rear when I was bleeding, though thinking about it, handbrake was on, and in Park. Doh. Bleed via usual methods, including clamp hoses and forcing caliper in. Front calipers are free on the slide pins. Rear pad wear looks even - not sure of any other way of checking rear calipers.
Was MOT'd in this condition. No printout, only adviso was the exhaust - normally he tells me about anything not right. If it was brake balance, would I be expecting the pull at all speeds and all braking types?
I can try to groom gayboy into giving the bushes a once over, as thats his fetish, but beyond that, really running low on ideas...
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Wishbones are original, but have been polyed at the front, and MDTM pressed in some rears.
No play felt in either track rods, or in idler. Will check pitman arm more precisely, but looked pretty straight earlier. Slight play in OSF wheel bearing.
No play found in rear when I was bleeding, though thinking about it, handbrake was on, and in Park. Doh. Bleed via usual methods, including clamp hoses and forcing caliper in. Front calipers are free on the slide pins. Rear pad wear looks even - not sure of any other way of checking rear calipers.
Was MOT'd in this condition. No printout, only adviso was the exhaust - normally he tells me about anything not right. If it was brake balance, would I be expecting the pull at all speeds and all braking types?
I can try to groom gayboy into giving the bushes a once over, as thats his fetish, but beyond that, really running low on ideas...
at low speeds nope.. but at higher speeds you will definitely feel the steering pulling to a side..
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it shows itself more under urgent braking where you apply maximum force..
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it shows itself more under urgent braking where you apply maximum force..
I need to test again, but I nailed the brakes earlier, duw to some idiot putting a hump back bridge on this country lane, and it braked well...
...seems to be that medium force braking that does it....
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any chance of air in brake lines :-\
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any chance of air in brake lines :-\
That was a possibility, thus I have rebled the brakes over last couple of days. I've also activated the ABS return pump several times, though not while bleeding, as a pain to do on your own...
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Front flexy hose breaking down causing it too bulge during hard brakeing then return back to normal :-\ :-\
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Front flexy hose breaking down causing it too bulge during hard brakeing then return back to normal :-\ :-\
Heavy braking seems to be fine...
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Its medium braking, moreso at 50+, the car noticeably pulls right, requiring steering left enough that releasing the brakes causes the car to snap left.
i've heard that braking wearing just socks can cause this. you need a sturdy pair of shoes imo :)
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Sticky caliper +1
Maybe there is a wear ridge on one caliper frame that prevents the pad from moving until 'firm pressure' is applied to the brake pedal?
I have never had a flex pipe break down internally but I have heard of it happening and causing mysterious problems :-\
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Had a 2.9 Granada that did similar. ABS pump was a bit slow. ie from cold the light would be a bit slow to go out.
Braking normally everything was fine, but every once in a while if you nailed the brakes only one side would work.(white face schocked smiley sitting in a brown patch). :o
Only solution was to prime the brakes by touching the pedal, releasing it, then stamping it down. Sold the car to someone at work who kept it a while, but never found out what the problem was. ISTR that the Teves ABS wasn't the most reliable system. :-\
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Been working on two theorys, as said. Its eather brakes or bushes.
Ime symptoms are quite similar but, differant in subtle ways.
If bushes, when braking, the car goes straight but the steering wheel turns in your hands.
If brakes, when braking, the car pulls and the driver has to steer into the pull to keep the car straight.
From a passengers view the symptoms look exactly the same, as the driver has the steering wheel at up to 30 degrees off centre when braking. But the driver feels a very differant sensation through the wheel in his hands depending if...brakes or bushes/pull or twist(of the steering wheel in your hands)
Having driven the car early on, just after bushes done iirc, the car pulled left to the kerb, and had to be steered right to keep straight. There was also a Falken tyres symotom present when driving but that was proved to be tyres :o and resolved....?
Given master has done the bushes, and the car has to be steered away from the pull, i rekon brakes.
Whats confusing us, is that the pull apears to have swapped sides, and was described as random at one point. Either that or one or both of us is getting muddled with old age. ;D
If brakes, is it posdibke air in the abs pump could move channels and cause the air,and hence the pull, to swap sides?
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Having driven the car early on, just after bushes done iirc, the car pulled left to the kerb, and had to be steered right to keep straight. There was also a Falken tyres symotom present when driving but that was proved to be tyres :o and resolved....?
Given master has done the bushes, and the car has to be steered away from the pull, i rekon brakes.
Whats confusing us, is that the pull apears to have swapped sides, and was described as random at one point. Either that or one or both of us is getting muddled with old age. ;D
If brakes, is it posdibke air in the abs pump could move channels and cause the air,and hence the pull, to swap sides?
I agree that it's most likely to be brakes, having been in the car for the tests.
I'm also a little confused with the sudden change of side, although you do have to remember that it had those awful clown tyres on when I was in it so the pull was a little random anyway :o :o
ABS is where I'd be looking, doing a proper bleed with an assistant so the pump can be run too :y Nearly cured the issue on my saloon but the w/b bushes were also suspect ::)
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Hi
I had this on a mfl omega, pass mot with 100% brake test but still would try turning left under light braking only, found that the drivers side front wishbone was defective at the front bush, totally f***d, went back the garage and told him won,t i thought,
replace both front wishbones, perfect, then you MUST have the front wheel aligment done :y :y
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Been working on two theorys, as said. Its eather brakes or bushes.
Ime symptoms are quite similar but, differant in subtle ways.
If bushes, when braking, the car goes straight but the steering wheel turns in your hands.
If brakes, when braking, the car pulls and the driver has to steer into the pull to keep the car straight.
From a passengers view the symptoms look exactly the same, as the driver has the steering wheel at up to 30 degrees off centre when braking. But the driver feels a very differant sensation through the wheel in his hands depending if...brakes or bushes/pull or twist(of the steering wheel in your hands)
Having driven the car early on, just after bushes done iirc, the car pulled left to the kerb, and had to be steered right to keep straight. There was also a Falken tyres symotom present when driving but that was proved to be tyres :o and resolved....?
Given master has done the bushes, and the car has to be steered away from the pull, i rekon brakes.
Whats confusing us, is that the pull apears to have swapped sides, and was described as random at one point. Either that or one or both of us is getting muddled with old age. ;D
If brakes, is it posdibke air in the abs pump could move channels and cause the air,and hence the pull, to swap sides?
Certainly possible air is still in there.
But, my understanding is that its a dual circuit, thus entirely independent, and not linked except at the reservoir above master cylinder, thus can't swap sides :-\
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Hi
I had this on a mfl omega, pass mot with 100% brake test but still would try turning left under light braking only, found that the drivers side front wishbone was defective at the front bush, totally f***d, went back the garage and told him won,t i thought,
replace both front wishbones, perfect, then you MUST have the front wheel aligment done :y :y
Front wishbones are polybushed at the front, and have recently had the rears replaced.
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Been working on two theorys, as said. Its eather brakes or bushes.
Ime symptoms are quite similar but, differant in subtle ways.
If bushes, when braking, the car goes straight but the steering wheel turns in your hands.
If brakes, when braking, the car pulls and the driver has to steer into the pull to keep the car straight.
From a passengers view the symptoms look exactly the same, as the driver has the steering wheel at up to 30 degrees off centre when braking. But the driver feels a very differant sensation through the wheel in his hands depending if...brakes or bushes/pull or twist(of the steering wheel in your hands)
Having driven the car early on, just after bushes done iirc, the car pulled left to the kerb, and had to be steered right to keep straight. There was also a Falken tyres symotom present when driving but that was proved to be tyres :o and resolved....?
Given master has done the bushes, and the car has to be steered away from the pull, i rekon brakes.
Whats confusing us, is that the pull apears to have swapped sides, and was described as random at one point. Either that or one or both of us is getting muddled with old age. ;D
If brakes, is it posdibke air in the abs pump could move channels and cause the air,and hence the pull, to swap sides?
Certainly possible air is still in there.
But, my understanding is that its a dual circuit, thus entirely independent, and not linked except at the reservoir above master cylinder, thus can't swap sides :-\
One or two sticking valves in the ABS block? :-\
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I am not convinced by the air theory. It only takes a tiny amount of air to cause a spongy brake pedal and I cannot image TB being content to drive a car with a spongy brake pedal ;)
Following up on the sticky caliper/piston theory I wonder if it could be a sticky shuttle in the master cylinder? (IIRC the Omega has dual circuit brakes. The brake pedal acts on the main piston in the master cylinder which sends fluid to the brakes on one side of the car but also applies fluid pressure to a floating piston (shuttle). The shuttle applies pressure to the brakes on the other side of the car. If the shuttle is sticking then light braking would only go to one side but heavy braking would go to both.)
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Been working on two theorys, as said. Its eather brakes or bushes.
Ime symptoms are quite similar but, differant in subtle ways.
If bushes, when braking, the car goes straight but the steering wheel turns in your hands.
If brakes, when braking, the car pulls and the driver has to steer into the pull to keep the car straight.
From a passengers view the symptoms look exactly the same, as the driver has the steering wheel at up to 30 degrees off centre when braking. But the driver feels a very differant sensation through the wheel in his hands depending if...brakes or bushes/pull or twist(of the steering wheel in your hands)
Having driven the car early on, just after bushes done iirc, the car pulled left to the kerb, and had to be steered right to keep straight. There was also a Falken tyres symotom present when driving but that was proved to be tyres :o and resolved....?
Given master has done the bushes, and the car has to be steered away from the pull, i rekon brakes.
Whats confusing us, is that the pull apears to have swapped sides, and was described as random at one point. Either that or one or both of us is getting muddled with old age. ;D
If brakes, is it posdibke air in the abs pump could move channels and cause the air,and hence the pull, to swap sides?
Certainly possible air is still in there.
But, my understanding is that its a dual circuit, thus entirely independent, and not linked except at the reservoir above master cylinder, thus can't swap sides :-\
One or two sticking valves in the ABS block? :-\
Doing tech2 tests for testing for air in the circuits activates pretty much every solenoid in there, in no glitches detected....
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I am not convinced by the air theory. It only takes a tiny amount of air to cause a spongy brake pedal and I cannot image TB being content to drive a car with a spongy brake pedal ;)
I agree. And I have some doubts as to whether it would cause uneven braking until it's very bad. My recollection of how a master cylinder works is that the circuits only separate when there is a a large difference in pressure between the two, so normally they act as one and are balanced.
I'm leaning towards a stuck caliper piston or slider, I think.
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I guess altzhiemers caused the swap sides theory then :-\ ;D
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There is also another thread with similar, also after bleeding brakes, but admitedly after numerous other suspension parts changed.
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Sticky piston (rather than slider), I would put money on it. Not much money mind. ::) ;D
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well there is extra "ballast" on the right hand side ::) :-X ;D
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why not swap wheels with another one to rule out these tyres (and wheels)?
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why not swap wheels with another one to rule out these tyres (and wheels)?
Swapped tyres front to back (can't swap sides, as directional), so less convinced its tyres.
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How can I test for a sticky piston in caliper?
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why not swap wheels with another one to rule out these tyres (and wheels)?
Swapped tyres front to back (can't swap sides, as directional), so less convinced its tyres.
I meant between cars ;)
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why not swap wheels with another one to rule out these tyres (and wheels)?
Swapped tyres front to back (can't swap sides, as directional), so less convinced its tyres.
I meant between cars ;)
So you are suggesting 2 problematic tyres on the car? ;)
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youre saying there are 4 mickey mouse tyres on TBE...
you also have a car with the identical fitment with 4 known good wheels and tyres...
for the sake of 1/2 an hour youve swapped em over and ruled em out.
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well there is extra "ballast" on the right hand side ::) :-X ;D
I'm heavier then him, but mine also pulls ;D :-X
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Swapped front pads over between drivers and passenger side. Sod all difference.
Same time, double checked sliders (move freely) and pistons (come out evenly and smoothly when she pumped the pedal with no pads in).
Kinda out of ideas now...
Is the front subframe held to chassis on bushes? :-\
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Swapped front pads over between drivers and passenger side. Sod all difference.
Same time, double checked sliders (move freely) and pistons (come out evenly and smoothly when she pumped the pedal with no pads in).
Kinda out of ideas now...
Is the front subframe held to chassis on bushes? :-\
no, just bft bolts.
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Swapped front pads over between drivers and passenger side. Sod all difference.
Same time, double checked sliders (move freely) and pistons (come out evenly and smoothly when she pumped the pedal with no pads in).
Kinda out of ideas now...
Is the front subframe held to chassis on bushes? :-\
no, just bft bolts.
Thats something else to rule out then. The 'possibilities' list is diminishing :'(
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So, are we saying the brakes are fine, properly blead, no air in abs pump...?
If so, then need to examine rearward front bushes...? Have polly been swapped to other side?
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So, are we saying the brakes are fine, properly blead, no air in abs pump...?
If so, then need to examine rearward front bushes...? Have polly been swapped to other side?
Well, I've rebled. Using the tech2 test to check for air, can't feel any. God knows if any still in modulator. Possible I guess.
Not swapped pollys over, but did get a prybar out earlier, fronts felt solid.
With both front wheels in the air, seems to be a lot of movement in the steering box, but seem to recall that being normal with engine off, and both front wheels up....
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Yes, up to an inch of slop at the steering wheel, say half inch at the road wheels perhaps...?
Should tighten up straight ahead. Is pitman arm straight ahead with steering wheel.
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Yes, up to an inch of slop at the steering wheel, say half inch at the road wheels perhaps...?
Should tighten up straight ahead. Is pitman arm straight ahead with steering wheel.
Cock, I knew there was something I wanted to check closely - it was blowing a friggin gale, so was keen to pack up ::)
It looked pretty straight, but I didn't check it that closely.
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Yes, up to an inch of slop at the steering wheel, say half inch at the road wheels perhaps...?
Should tighten up straight ahead. Is pitman arm straight ahead with steering wheel.
Cock, I knew there was something I wanted to check closely - it was blowing a friggin gale, so was keen to pack up ::)
It looked pretty straight, but I didn't check it that closely.
as i recall, going by steering lock position comparison at Kasham stadium your isnt any further out than mine, not fully clued up on that mechanics though.
...and yes bix should tighten up with engine running.
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Yes, up to an inch of slop at the steering wheel, say half inch at the road wheels perhaps...?
Should tighten up straight ahead. Is pitman arm straight ahead with steering wheel.
Cock, I knew there was something I wanted to check closely - it was blowing a friggin gale, so was keen to pack up ::)
It looked pretty straight, but I didn't check it that closely.
as i recall, going by steering lock position comparison at Kasham stadium your isnt any further out than mine, not fully clued up on that mechanics though.
...and yes bix should tighten up with engine running.
And in all other driving aspects other than medium braking, the car handles as expected. Bit of tramlining, but with the amount of camber it runs, thats to be expected?
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Is it a brake inbalance or a pull under braking?
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Is it a brake inbalance or a pull under braking?
Not sure how I'd tell the difference :-[
MOT'd last month, with this issue (although assumed it was related to poor geometry then, so never asked about imbalance, but not mentioned at MOT).
Stamp of the brakes, it stops straight as far as I can tell.
Brake with medium effort at cruising speeds, and it veers right, causing you to steer into it. Releasing the brake shows how much angle you've had to give it, as it veers left ;D
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Is it a brake inbalance or a pull under braking?
Not sure how I'd tell the difference :-[
MOT'd last month, with this issue (although assumed it was related to poor geometry then, so never asked about imbalance, but not mentioned at MOT).
Stamp of the brakes, it stops straight as far as I can tell.
Brake with medium effort at cruising speeds, and it veers right, causing you to steer into it. Releasing the brake shows how much angle you've had to give it, as it veers left ;D
Other than braking, drives pretty straight, has 1'34 camber each side, slight tendency to tramline.
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Yep, mine has -1.40 base setting and there is some tram lining. Back to 1.20 for me i think. :-\
Tried the foot on wheel test? Any slop for and aft.?
Maybe get somebidy to drive the car and brake, while you look from outside the car for toe out as the car brakes...?
Either side on, or head on? .... Although not sure how that would help i.d the fault thinking about it.
Or find a small kerb, like a down in a drive way about an inch high like mine for instance, and have an assistant drive over it slowly on neutral throttle without braking, see if the front road wheels move the same. Obviously there will be vertical suspension movement, but your looking for uneven for and aft slop in the road wheel. Watch spcifically at the gap between tyre and sill, if one wheel moves rearward to the sill when driving over a 1 inch or higher kerb, and the other doesnt, or the movement is uneven, then theres a bush or wishbone/control arm problem.
Who do we know with a long pit...? Btw... :-X
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Swapped front pads over between drivers and passenger side. Sod all difference.
Same time, double checked sliders (move freely) and pistons (come out evenly and smoothly when she pumped the pedal with no pads in).
Kinda out of ideas now...
Is the front subframe held to chassis on bushes? :-\
So not considering a faulty master cylinder as the cause then :-\
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Idler arm ok?
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Idler arm ok?
Was rock solid when started investigating, a while ago now though.
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Who do we know with a long pit...? Btw... :-X
I only have a little one...
But I hear it's not the size that counts... ;D
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I know its been mentioned earlier but I have had flexy hoses that have bulged internally and can cause this sort of problem,last one I had like it suffered very similar symptoms to yours,ie it was ok when brakes were planted but caused a pull under normal braking. The giveaway was that when the bleed nipples were loosened fluid would drip from the good side but not the bad one unless brake pressure was applied.Maybe worth a try !.
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Idler arm ok?
Last knackered idler really showed up in normal driving, which is fine on this car. This one has no vertical play.
I have a good one that I removed from MV6 last winter, again purely chasing a handling issue, that turned out not to be the idler. Worth putting that on anyway?
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Swapped front pads over between drivers and passenger side. Sod all difference.
Same time, double checked sliders (move freely) and pistons (come out evenly and smoothly when she pumped the pedal with no pads in).
Kinda out of ideas now...
Is the front subframe held to chassis on bushes? :-\
So not considering a faulty master cylinder as the cause then :-\
Nothing ruled out, but reading Kevin Wood's reply was put it further down the list.
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I know its been mentioned earlier but I have had flexy hoses that have bulged internally and can cause this sort of problem,last one I had like it suffered very similar symptoms to yours,ie it was ok when brakes were planted but caused a pull under normal braking. The giveaway was that when the bleed nipples were loosened fluid would drip from the good side but not the bad one unless brake pressure was applied.Maybe worth a try !.
With an easibleed, fluid comes out at about the same rate each side (when both nipples open at same time)
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Update to conclude this thread :D
Turned out the wishbone bolts had loosened.
Problem solved
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Update to conclude this thread :D
Turned out the wishbone bolts had loosened.
Problem solved
:o :o :o :o :o
Loosened or operator error on tightening? ::) ::)
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Update to conclude this thread :D
Turned out the wishbone bolts had loosened.
Problem solved
:o :o :o :o :o
Loosened or operator error on tightening? ::) ::)
We will never know for certain.
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Update to conclude this thread :D
Turned out the wishbone bolts had loosened.
Problem solved
:o :o :o :o :o
Loosened or operator error on tightening? ::) ::)
We will never know for certain.
Although I have vague recollections of watching them being torqued, and even assisting in holding the vertical bolt from the engine bay.
Can't say if we got the right torque settings, made a mistake, whatever, or if they have simply loosened.
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Fair enough... Never known them work loose though, particularly in the short time/mileage they have been fitted ;)
Worrying though :o :o
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Update to conclude this thread :D
Turned out the wishbone bolts had loosened.
Problem solved
:o :o :o :o :o
Loosened or operator error on tightening? ::) ::)
Hmm, I wonder if this really is the end of the thread.
Not saying it has happened but there is a risk when bolts through holes in sheet steel have been loose for the holes to wear oval.
I have discovered this on a Range Rover axle I was refurbishing. I fixed it by adding new metal with a welder and filing/grinding away the excess to make a nice neat hole. (I haven't had it apart since but it seems to have done the trick :) )
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Update to conclude this thread :D
Turned out the wishbone bolts had loosened.
Problem solved
:o :o :o :o :o
Loosened or operator error on tightening? ::) ::)
Hmm, I wonder if this really is the end of the thread.
Not saying it has happened but there is a risk when bolts through holes in sheet steel have been loose for the holes to wear oval.
I have discovered this on a Range Rover axle I was refurbishing. I fixed it by adding new metal with a welder and filing/grinding away the excess to make a nice neat hole. (I haven't had it apart since but it seems to have done the trick :) )
Indeed, nut he should be OK as I doubt the car has done more than 300 miles since they were fitted ;)