17 replies to this topic

[Haynes]

Having problems as my heater seems to be leaking from where the pipe attaches to the heater, however it only seems to do it intermittently.  And I also had a problems with where the other end connects to the bottom hose via a piece of pipe, i ended up putting some sealer on it.

 

The car is a Mk1 super deluxe and the hose is 1/2" ID standard stuff from minispares.  It is marked up as 1/2" / 13mm.

 

My question is the pipe a little too large a bore for the early cars?  Or is the rubber quality these days such that its a bit more slippery and more reluctant to grip and seal?  Is there a better or more original type of pipe out there?

[Vanman20]

Are you using good quality jubilee clips ?

[Tornado99]

I assume there are some hose clamps involved that you have checked/snugged up?
Are you seeing leak from between hose and connection pipe or could there be a crack in the pipe or hose?
You said intermittant, do you see leaks only once car is fully warmed up? This means coolant is under pressure. How much pressure depends on your radiator pressure cap condition and its rating. If this is bad, you could be over pressurizing whole system and the leak happens at heater core. Get the cap tested at an auto shop or just renew it if its old.

[sonscar]

As noted above poor quality or incorrectly sized clips form a D shape rather than a circle and thus a poor seal,Worth a try,Steve..

[gazza82]

Mikalor clamps are better than the old jubilee or clamp types ...

[slidingdog]

I'm also having this problem, albeit with a new matrix and hose....leaks only when the engine is warm, but I also have a new rad cap so I assume it's not over pressurised(?).

 

The new matrix has plastic stubs http://www.minispare...ix/37H7216.aspx, I reused the old jubilee clips which look good quality, I assume are the factory ones (looks like this one: http://www.minispare...nts/3H2963.aspx). Tightening it makes the leak worse and loosening it makes the leak worse.....

 

Is there a trick to get a good seal? Can I use gasket sealant or ptfe tape or something? Or should I just be looking at mikalor clips?

 

Many thanks,

 

Tim
 

[cal844]

Do you have the hose all the way down at the body end of the stub? I've found I need 2 or 3 mm between the end of the hose and the body end of the stub.

I use jubilee clips and never had an issue with hoses not sealing, it could be either too loose or too tight, or too far up the stub.

Edited by cal844, 28 September 2021 - 03:22 PM.

[slidingdog]

Do you have the hose all the way down at the body end of the stub? I've found I need 2 or 3 mm between the end of the hose and the body end of the stub.

I use jubilee clips and never had an issue with hoses not sealing, it could be either too loose or too tight, or too far up the stub.

Hi Cal yes i have the hose pushed all the way on - I'll try pulling it off a few mm and see if that helps. Thanks!

[Tornado99]

Are the hoses new and correct diameter? Old rubber may not seal well. Try a different type of hose clamp, with better shape all around than standard jubilee type. Also check the plastic stubs don't have any moulding flash or uneveness such as a seem etc that could make a leak point. Try filing, sanding them smooth.

Edited by Tornado99, 28 September 2021 - 04:57 PM.

[cal844]

Do you have the hose all the way down at the body end of the stub? I've found I need 2 or 3 mm between the end of the hose and the body end of the stub.

I use jubilee clips and never had an issue with hoses not sealing, it could be either too loose or too tight, or too far up the stub.

Hi Cal yes i have the hose pushed all the way on - I'll try pulling it off a few mm and see if that helps. Thanks!

It's worth trying, it's easy enough to move around a little as needed

[slidingdog]

Thanks Cal and Tornado, pulling the hose off a few mm made a big difference, no leaks during 10mins or so idling, but some time shortly after switching the engine off a little puddle appeared. Dried it off and checked again this morning to find a few more drops. When I moved the hose it was really quite easy to slide, so wondering if the plastic stubs of the new matrix are slightly smaller than the copper of the old one...

 

Will order some mikalor clamps and try those next...

 

Best,

 

Tim

Edited by slidingdog, 29 September 2021 - 01:55 PM.

[Tornado99]

Thanks Cal and Tornado, pulling the hose off a few mm made a big difference, no leaks during 10mins or so idling, but some time shortly after switching the engine off a little puddle appeared. Dried it off and checked again this morning to find a few more drops. When I moved the hose it was really quite easy to slide, so wondering if the plastic stubs of the new matrix are slightly smaller than the copper of the old one...

 

Will order some mikalor clamps and try those next...

 

Best,

 

Tim

Seems to me, if the hoses slide easily on the stubs, then they may be too large an ID on the stubs. Should take some good force/twisting to fit for best sealing. You could try disconnecting, cleaning/drying the stubs, using automotive silicone sealant on the stubs before tightening down the clamps. Can you use two clamps per stub to better seal it? 

Edited by Tornado99, 29 September 2021 - 06:25 PM.

[slidingdog]

Seems to me, if the hoses slide easily on the stubs, then they may be too large an ID on the stubs. Should take some good force/twisting to fit for best sealing. You could try disconnecting, cleaning/drying the stubs, using automotive silicone sealant on the stubs before tightening down the clamps. Can you use two clamps per stub to better seal it? 

 

I think you may be right. My nice chunky mikalor clamp arrived yesterday, got it fitted today and all looked good, but once again it leaked once the engine got warm, albeit less than before with the factory clamp. Then the other matrix hose started leaking too

 

I measured an offcut of the hose I used against the original one I took off, .5-.51" compared to the old .48-.49", I guess that difference is enough to cause a leak under pressure. Probably means the leak I assumed the original matrix had after fitting new hoses was not actually the matrix

 

Do you think it's worth trying a different hose (got that one from Minispares) or is it fine to use sealant for a long-term fix (I have some Elring Dirko HT in the garage, I assume that will be suitable)?

 

Many thanks again!

 

Tim

[Tornado99]

 

Seems to me, if the hoses slide easily on the stubs, then they may be too large an ID on the stubs. Should take some good force/twisting to fit for best sealing. You could try disconnecting, cleaning/drying the stubs, using automotive silicone sealant on the stubs before tightening down the clamps. Can you use two clamps per stub to better seal it? 

 

I think you may be right. My nice chunky mikalor clamp arrived yesterday, got it fitted today and all looked good, but once again it leaked once the engine got warm, albeit less than before with the factory clamp. Then the other matrix hose started leaking too

 

I measured an offcut of the hose I used against the original one I took off, .5-.51" compared to the old .48-.49", I guess that difference is enough to cause a leak under pressure. Probably means the leak I assumed the original matrix had after fitting new hoses was not actually the matrix

 

Do you think it's worth trying a different hose (got that one from Minispares) or is it fine to use sealant for a long-term fix (I have some Elring Dirko HT in the garage, I assume that will be suitable)?

 

Many thanks again!

 

Tim

 

Well the sealant suggestion was just an attempt to get it going. Would not like to have it there long term....might work though, worth a try?  If it fails, you can still try finding a tighter fitting hose. If the matrix stubs are a plastic, then over tightening the hose clamps might be distorting the plastic enough to make for a poor seal with the hose. With tighter fitting hose, there should be less need to use higher clamping force, assuming the stubs are not permanently distorted or cracked. Make sure there is no protruding plastic on the stubs from the moulding process etc... Can be knocked down with a bit of emery paper or similar. 

[Quinlan minor]

Just a thought, but might it be worth copying the solution used on plastic MPi header tanks?

Slide a tight fitting metal sleeve inside the plastic stub to stop it deforming when clamped.