11 replies to this topic

[Rubbershorts]

Hi everyone. The latest problem I have is a small pool of fluid on the drivers side rubber mat. It's happened the last 3 times I've been out. It's not much but needs stopping. Tonight I dismantled the heater unit and did find moisture at that side of the unit. It's definitely the water coolant mix you'd expect. Anyway, gave it a wipe and started the engine. Left it running to get to running temp and flicked the fan switch on for what it's worth. No leak. Left it to cool down, no leak. Anyone had a similar experience? Cheers, Daz.

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[ac427]

Perhaps pressure testing the heater matrix might reveal the origin of the leak?

[Rubbershorts]

Quick reply, thanks. How is the pressurising test carried out? Can it be done whilst it's still in the car?

[68+86auto]

Quick reply, thanks. How is the pressurising test carried out? Can it be done whilst it's still in the car?

 

You need a cooling system pressure tester. it goes on the radiator filler neck and pressurises the system.

[Rubbershorts]

A quick Google for these kits throws up a lot of options with various radiator adapters. Could anyone point me in the direction a cheap, UK based kit that will definitely fit my 93 Rio? Also, any ideas on why the matrix would leak and then not leak?

[Chris1275gt]

When the water heats up and becomes pressurised the metal expands and as probably in your case the small crack or small pinhole will open up and leak when it cools down it will close up and stop leaking. I’d just swap it for a new one.

[Rubbershorts]

When the water heats up and becomes pressurised the metal expands and as probably in your case the small crack or small pinhole will open up and leak when it cools down it will close up and stop leaking. I’d just swap it for a new one.

I figured that was what was happening, but it didn't do it whilst testing last night. I think you're right though, save future hassle and change it whilst it's in bits. Is it easy to get the exact one? Read a bit about after market not quite matching up with the exit holes in the heater.

[sonscar]

 Does it have the plastic bit with the heater pipes held by screws and O rings?Steve.

[Rubbershorts]

 Does it have the plastic bit with the heater pipes held by screws and O rings?Steve.

 

 

Hi Steve, can't remember fully what it looked like, the car is at home,  but the pipes were attached on the outside of the heater unit with 2 jubilee clips.

 

[Rubbershorts]

It was similar to this set up. In that the clip were external and in this configuration.

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Edited by Rubbershorts, 20 September 2024 - 09:23 AM.

[68+86auto]

A quick Google for these kits throws up a lot of options with various radiator adapters. Could anyone point me in the direction a cheap, UK based kit that will definitely fit my 93 Rio? Also, any ideas on why the matrix would leak and then not leak?

 

That just has a standard radiator cap right?

 

Most testers will have an adaptor that fits. They usually just look like a cap but with a fitting on it.

[Rubbershorts]

Thanks for your input guys. Figured in the end that as it's definitely coming from the heater matrix there's probably not much to be gained with the pressure tester at this stage. I've learnt though, that leaks anywhere else, a bit less obvious, would be identified this way. So thanks for that. Changed the matrix for a new one today and took the opportunity to clean out the heater box and replace all the foam. Been for test and everything is running sweet with less rattles.