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[Webby the Bear]

......Has anyone ever tried replacing the transfer pipe with a standard coolant hose? Last time I did my stat was a couple of years ago and I wonder off the top of my head if there'd be room behind the rear cam back plate to get a regular hose.

Reason I wonder is cos the barsteward bolt I crossed last time and I'm concerned about its ability to keep the transfer pipe in the correct orientation.

Secondly it would obviously make stat replacement a bloody sight easier

Thoughts please 👍

[Shackeng]

IIRC the problem will be the space available to get it in with a clip to hold it in place, and remember the seal(s) to the OE pipe.

[JamesV6CDX]

The outlet of the 'stat doesn't have a lip, and isn't ideal for connecting a hose to.

The correct approach will be to remove the existing stat/housing and transfer pipe, and then inspect / clean / repair the thread on the securing bolt as necessary.

When you say you crossed the bolt - did you continue to force it tight after realising it was cross threaded, or did you remove it and refit - and did it torque up OK?

The bolt doesn't need significant torque just to hold the transfer pipe in place*, you may find chasing the threads, and doing it up using some thread lock, may suffice.

You are right that the pipe must be secure, though. If it's not, it will soon work it's way out under coolant pressure, and go with a bang


*The bolt does also hold the lifting eye, so it would need to be at full strength if ever you were removing the engine

[Doctor Gollum]

IIRC the problem will be the space available to get it in with a clip to hold it in place, and remember the seal(s) to the OE pipe.

Not to mention the shape of the stat pipe socket casting and the different diameters, not to mention the extra length and squeezing it under the cams and chaffing...

Remember kids, No means No

[Nick W]

The outlet of the 'stat doesn't have a lip, and isn't ideal for connecting a hose to.

The correct approach will be to remove the existing stat/housing and transfer pipe, and then inspect / clean / repair the thread on the securing bolt as necessary.


The bolt doesn't need significant torque just to hold the transfer pipe in place*, you may find chasing the threads, and doing it up using some thread lock, may suffice.

You are right that the pipe must be secure, though. If it's not, it will soon work it's way out under coolant pressure, and go with a bang

I have to disagree, as mine hasn't had a bastard bolt in since before I did the head gaskets three years ago! That was when I discovered that half the threaded boss had broken off   Fixing it would have meant welding it up and retapping, or a new head. I crossed my fingers, spilt some more blood to the DIY gods and put it back together. It was a concern then, but I stopped worrying about it some time later, after I changed the coolant hose twice(once for a temporary used one in barely any better condition than the split one I removed, and a new one soon after).

[JamesV6CDX]

The outlet of the 'stat doesn't have a lip, and isn't ideal for connecting a hose to.

The correct approach will be to remove the existing stat/housing and transfer pipe, and then inspect / clean / repair the thread on the securing bolt as necessary.


The bolt doesn't need significant torque just to hold the transfer pipe in place*, you may find chasing the threads, and doing it up using some thread lock, may suffice.

You are right that the pipe must be secure, though. If it's not, it will soon work it's way out under coolant pressure, and go with a bang

I have to disagree, as mine hasn't had a bastard bolt in since before I did the head gaskets three years ago! That was when I discovered that half the threaded boss had broken off   Fixing it would have meant welding it up and retapping, or a new head. I crossed my fingers, spilt some more blood to the DIY gods and put it back together. It was a concern then, but I stopped worrying about it some time later, after I changed the coolant hose twice(once for a temporary used one in barely any better condition than the split one I removed, and a new one soon after).

A while ago I would have agreed wholeheartedly with you, however having had a different experience myself, I now have to disagree.

My transfer pipe on my old 99 Elite never had a bastard bolt and it listerally appeared that it had welded itself to the stat housing. I thought no more of it, until one day it just blew off with no warning, in the most inconvenient place and time

As such, I can only stick by my comment that the B bolt is essential, in order to hold the pipe in 

[Webby the Bear]

Putting a lip on the stat housing portion wouldn't be a problem. And I removed the lifting eye long ago 

[Nick W]

I have to disagree, as mine hasn't had a bastard bolt in since before I did the head gaskets three years ago! That was when I discovered that half the threaded boss had broken off   Fixing it would have meant welding it up and retapping, or a new head. I crossed my fingers, spilt some more blood to the DIY gods and put it back together. It was a concern then, but I stopped worrying about it some time later, after I changed the coolant hose twice(once for a temporary used one in barely any better condition than the split one I removed, and a new one soon after).

A while ago I would have agreed wholeheartedly with you, however having had a different experience myself, I now have to disagree.

My transfer pipe on my old 99 Elite never had a bastard bolt and it literally appeared that it had welded itself to the stat housing. I thought no more of it, until one day it just blew off with no warning, in the most inconvenient place and time

As such, I can only stick by my comment that the B bolt is essential, in order to hold the pipe in 

I'm not convinced that my limited aluminium welding skills and small TIG are up to working on a cylinder head, so would consider welding the transfer tube to a new thermostat housing. A stepped clamp off an exhaust manifold stud would probably be the solution if I was worried about it.

[Webby the Bear]

IIRC the problem will be the space available to get it in with a clip to hold it in place, and remember the seal(s) to the OE pipe.

Not to mention the shape of the stat pipe socket casting and the different diameters, not to mention the extra length and squeezing it under the cams and chaffing...

Remember kids, No means No

Which is why I said in my first paragraph I wonder if there's room 

The different diameters of pipe wouldn't be an issue as I could easily make some kind of adapter up. And as I said I could make a lip on the stat housing portion to be able to accept a hose.

My main concern would be the aforementioned chafing should the space behind be so narrow. So maybe it's a no goer. But hey if I do try it and it works life is sweet 

[X30XE]

You have to wonder why they felt it necessary to use that stupid tube in the first place. Perhaps there's a good reason.

[Webby the Bear]

You have to wonder why they felt it necessary to use that stupid tube in the first place. Perhaps there's a good reason.

Yup, hence the question 

[YZ250]

You have to wonder why they felt it necessary to use that stupid tube in the first place. Perhaps there's a good reason.

The tube itself doesn't bother me, I just wish that GM would have made it 10mm shorter so that the stat and the transfer pipe complete would come out the valley end.     The later engines have two bastard bolts, one for the transfer pipe and one for the dipstick. 

[Nick W]

The tube itself doesn't bother me, I just wish that GM would have made it 10mm shorter so that the stat and the transfer pipe complete would come out the valley end.

They come out complete once you've removed the cambelt backing plate. But as that is another couple of hours work, it's only worth doing if you're lifting the cylinder heads.

[X30XE]

I don't remember it being that problematic when I did mine. Getting the stat housing to let go of the tube was the only fight I remember. 

[YZ250]

The tube itself doesn't bother me, I just wish that GM would have made it 10mm shorter so that the stat and the transfer pipe complete would come out the valley end.

They come out complete once you've removed the cambelt backing plate. But as that is another couple of hours work, it's only worth doing if you're lifting the cylinder heads.

After getting hacked off using the rational approach of twisting the stat off the pipe, I have a tried and tested method. Leave the stat bolted down, remove the rubber hose from the pipe, split the transfer pipe off and away you go, piece of cake.    I feel it hasn't had the chance to wear me down that way.