940 Heater Control Valve

[Laird Scooby]

Originally Posted by vickyg

Now I come to removing said leaky valve I don't think the one in my car is for the 940 either. It doesn't look right at all! What do you folk think?

That actually looks like it's leaking from the join where the hose meets the matrix. All the blue crystals suggest either antifreeze/coolant or perhaps verdigris, either of which could come from a leak. Also the outside of the hose looks sweaty suggesting the coolant has run down the outside of the hose. Might be worth removing and inspecting the hose in the ends, see if it's collapsed/perished.

[tofufi]

That doesn't look like the one that came out of my 740

[vickyg]

Yes there is coolant running up and down the hose and now it's cooler condensation on the bulkhead. I don't think the matrix is leaking but the jubilee unions are definitely suspect. I think someone has historically tried to fix and possibly made it worse. This may be a better pic as you can see the valve peaking out. I see no white plastic lever or arm however.

PS exactly how long do you stay a new member in this group? 12 years seems a mighty long time :-p

[Ian21401]

Originally Posted by Laird Scooby

That actually looks like it's leaking from the join where the hose meets the matrix. All the blue crystals suggest either antifreeze/coolant or perhaps verdigris, either of which could come from a leak. Also the outside of the hose looks sweaty suggesting the coolant has run down the outside of the hose. Might be worth removing and inspecting the hose in the ends, see if it's collapsed/perished.

Agree with Dave’s comments.
Suggest get the valve and fixings out so that it may examined more closely. When I had a leak problem many years ago I was able to obtain a new OE replacement so didn’t investigate the old valve too much, BUT, the operating parts of the old valve appeared to be ok. The leak was caused by a deformed input pipe which came through the bulkhead. The plastic pipe had been crushed by previous over tightening of the hose clip on the engine side of the bulkhead and coolant was weeping out and migrating through the bulkhead onto the outside of the valve assembly then dripping off. It’s possible that if I had needed to do so I may have been able to somehow replace that deformed input pipe.
You may find that you have a similar problem with that matrix/hose joint.

[vickyg]

I should probably mention the heater control on the dash does not operate the valve as it should so I fear the valve is seized. I will see if I can ease the cables etc. when I get it off. I can open and close it by hand and if opened the heater control will close it (sometimes) - just need to remove a sofa from my workshop and it's going in!

[Laird Scooby]

Originally Posted by vickyg

Yes there is coolant running up and down the hose and now it's cooler condensation on the bulkhead. I don't think the matrix is leaking but the jubilee unions are definitely suspect. I think someone has historically tried to fix and possibly made it worse. This may be a better pic as you can see the valve peaking out. I see no white plastic lever or arm however.

PS exactly how long do you stay a new member in this group? 12 years seems a mighty long time :-p

It's a black operating arm on that valve. It really doesn't matter what colour it is as long as it works.

Being a "New Member" is down to the number of posts you've made, i'm not sure on the figures but the more posts you create, the faster you'll become something other than "New".

Originally Posted by vickyg

I should probably mention the heater control on the dash does not operate the valve as it should so I fear the valve is seized. I will see if I can ease the cables etc. when I get it off. I can open and close it by hand and if opened the heater control will close it (sometimes) - just need to remove a sofa from my workshop and it's going in!

The valve probably isn't seized if you can operate it by hand and it's down to adjustment of the heater control cable. A drop of light oil (3-in-1 or similar) in the high end of the cable followed by some "exercise" preferably with the valve end disconnected to minimise physical resistance to the cable moving should get the cable moving correctly but likely to need adjustment as well - it's 30 years old or thereabouts and has probably stretched slightly through use over that time.

I've heard of having a comfy workshop but a sofa is taking it extremes!

[vickyg]

Sofa is now gone, so time to move in the 940 sofa on wheels

[vickyg]

It seems I have to disconnect the hose engine side of the bulkhead? From other threads I wasn't expecting this. Has anyone tried K seal to fix one of these valve? Thinking it's worth a go before a bigger job ensues.

[Laird Scooby]

Originally Posted by vickyg

It seems I have to disconnect the hose engine side of the bulkhead? From other threads I wasn't expecting this. Has anyone tried K seal to fix one of these valve? Thinking it's worth a go before a bigger job ensues.

I wouldn't advise K-Seal or any other similar products to fix the valve. Chances are it's the unions, wouldn't be surprised to find they have made the pipework oval because someone has over-tightened the clips and this has caused the leaks.

From what i can see from your previous photos, you shouldn't have to disconnect anything in the engine bay but it might be a good idea so the footwell doesn't fill with coolant when you disconnect the valve.

[Ian21401]

I may be mistaken about the input pipe on the valve. I thought that it poked through the bulkhead and the hose was connected to it on the engine side of the bulkhead, but there’s a good chance that I’m wrong and the hose comes through the bulkhead before joining the input pipe. That seems more likely as the poor connection was leaking coolant into the car. I cannot be sure without checking mine and it’s persisting down outside.