Heater Valve

[ashje]

So i snapped a stub pipe going through the firewall, i've taken all of the matrix pipes and core out just to make sure everything else is ok whilst i'm there.

I've already got some new o rings for both of the pipe to core connections as preventative maintenance but i'm also noticing that the valve has some green gunky stuff around it.

I never had any leaks but is there any maintenance i can do to the valve or is it just a case of buying new?


Also occasionally the blower would rise and fall in speed erratically, any ideas as to the cause?

Thanks
Ash

[DHFiS]

I have drilled out the rivets holding the valve together and replaced the O ring in mine when it started leaking. The rivets can be replaced with bolts for reassembly.

If you have evidence of a leak now it can only get worse in time.

[Brianmoooore]

Most important 'maintenance' for the electric valve is to make sure that the coolant tank pressure cap is in good order, and doesn't over pressurize the system.
The fan motor has plain bush bearings, and after thirty years will most likely be crying out for lubrication. To do this effectively, the motor needs to be removed from the car, the bearings freed up and cleaned with WD40 or similar, then lubricated with a light oil. The motor should be powered up from a battery while in your hand while doing this, to ensure that the cleaning fluid and lubricant work their way right into the bearings.

[Carmo13]

Most important 'maintenance' for the electric valve is to make sure that the coolant tank pressure cap is in good order, and doesn't over pressurize the system.

I recently had problems with my cooling system.
Firstly my top radiator hose blew up like a balloon and then the rivets in the heater valve failed and i had coolant flooding into the interior. Both of these failures could relate to excess pressure in the system.

When everything was sorted and i refilled with coolant, i checked the pressure cap and it has a large amount of sludge/scale on the inside which could have easily stopped the pressure valve working properly. After cleaning the cap i have had no furthur problems so it could have easily been the cause of the problems.

Definitly worth checking.

[ashje]

Cheers guys, I will definitely check the cap and i have a spare valve i'm going to take apart and clean up.

With regards to the o ring inside the valve, where is it available from?

I will also remove the motor, is it a major task to clean and strip the bearings?

[Brianmoooore]

If the cap is a 1.4 bar one, check that it's not the original. There was a safety recall on these in 1996, but there's still plenty out there that missed it. Most of the replacement caps can be identified by a large yellow disc on their base that was black on the originals.
The fan motor doesn't need to be stripped in any way, but it does need to be removed from the car. Hold the motor with the shaft vertical so that gravity helps get the WD40 and oil into the bearings, move the shaft up and down as far as it will go, and power it up from a battery. Repeat until the motor shaft spins freely and is fully lubricated.