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Coolant leaks
pk - 7/6/06 at 12:08 PM

Why is it I always get the difficult to solve problems?

I’m having trouble with coolant leaks! 38mm ally tube and 38mm Samco hose clamped using Jubilee clips. I originally used Gates hose but found I was over tightening the clips, stripping the threads trying to stop the water leaks. So I splashed out (no pun) on Samco hose which is a lot softer but after doing the clips up tighter and tighter trying to stop the leaks I still have leaks! The ally tube is new and round, no flats, the Samco is new as are the clips – aaarrrrggg. I’ve never come across this trouble before, it’s becoming a real pain in the proverbial!


flak monkey - 7/6/06 at 12:13 PM

Is the end of the pipe straight/smooth? If so thats where your problem lies I suspect....

David


pk - 7/6/06 at 12:19 PM

Pipe ends are straight – but roughened up to remove the gloss and give the tube something to grip on. If you are correct and it’s the tube ends, what’s the theory?


NS Dev - 7/6/06 at 12:23 PM

should be no problem with plain pipe ends, thats all I have ever used on numerous car builds.

The alloy pipe should be a snug fit into the end of the silicone pipe to start with. Clean the end of the alloy pipe with scotchbrite or fine emery, then wipe out the end of the silicone pipe with a rag with wd40 on it.

Push together and the key, use decent jubilee clips!! I bought some from screwfix then they stripped before they were even tight, I've binned the lot now and bought proper ones!


flak monkey - 7/6/06 at 12:25 PM

The ends of the tubes really need a lip or barb on them to stretch the pipe a bit (like you get on a radiator other push fit pipe connection). Once clamped up with a lovelyjubbly clip it should then not leak. There are places around that will make up custom lengths of coolant pipe. Car Builder Solutions being one of them.

http://www.nfauto.co.uk/cut_tubes.htm

I dont think there would be a problem if you used, say 40mm pipe and pushed 38mm hose on it then clipped it. I stand to be corrected though.

David


pk - 7/6/06 at 12:28 PM

I cleaned and scotchbrighted the tube ends first. The only thing I didn’t do was clean the Samco and come to think of it there is a possibility that the release agent has something to do with it. I’m using blue antifreeze but the little drips that are still attached are sometimes red!!


NS Dev - 7/6/06 at 12:30 PM

undoubtedly having the lipped pipe will be a better solution, but I have never had the facility to put the lip on, and have done a lot of engine conversions and full car builds and never used a lipped pipe yet.

The key is making sure the pipes are the right size to start with (same od solid pipe as flex pipe bore) and using decent stainless jubilee clips.

Also, especially if reusing hoses, never underestimate the ability of WD40 to help the hose to seal. It softens the rubber slightly and allows a much better seal.


pk - 7/6/06 at 12:31 PM

And before i forget the clips are brand new Jubilee clips - quality items. They are wider that those new thin stainless one's found on Jap cars and bikes.

I suspect the release agent has something to do with this?


johnemms - 7/6/06 at 12:50 PM

stp radiator leak fixer stuff... dont it stay in your system and stop future leaks??

just a thought....


NS Dev - 7/6/06 at 12:54 PM

quote:
Originally posted by pk
And before i forget the clips are brand new Jubilee clips - quality items. They are wider that those new thin stainless one's found on Jap cars and bikes.

I suspect the release agent has something to do with this?


sounds like it may do, I presume you mean the waxy stuff they use to release the tube off the mandrel after curing?

Usually they clean it all off but I have had a few with wax still on them.


nitram38 - 7/6/06 at 01:19 PM

I have aluminuim pipes. I put 3 tig welds on the ends of the pipes, pushed the hose over them and jubileed behind them. That way they cannot come off.

[Edited on 7/6/2006 by nitram38]


02GF74 - 7/6/06 at 01:32 PM

is there room to slap on another clip or two? won't look nice but should help or use el cheapo rubber hose?


Danozeman - 7/6/06 at 04:13 PM

quote:

is there room to slap on another clip or two? won't look nice but should help or use el cheapo rubber hose?



If you can put 2 clips on.

If u clean up both mating surfaces with brake cleaner. Make sure they are both dry and no oily. Ally pipe to samco should seal a treat.