Tom in Austin

Should the back of the thermostat touch the seal in the water bridge when cold/before opening?

Reassembling mine and just wondering b/c there's a gap approx 4-5 mm. Never know, might be more than one type of waterbridge or t-stat out there ...

davek9

it was always my impression that it need to close off that path to work correctly, else why have a seal, right?

bureau13

It should touch it at some point, but I don't remember if that point is hot or cold. Remember that our thermostats work "backwards," so you can't drive around without one and just take longer to come up to temp.

In fact, thinking about it some more, it has to be hot when it seals, because when mine was bad (nothing left but the metal ring) my car would consistently run hot. That tells me that when cold, it must be unsealed.

davek9

agreed ^^^ thinking further when they open they move back, so yep they would / should seal

StratfordShark

Yes, the t-stat opens above 83C (I think there's a 75C too) and seals against the bypass port at back of coolant bridge, so the coolant then circulates via the bottom hose through the rad

Bertrand Daoust

It should be close (compressed) when cold. Open (extended) when warm.
A good description on this here:





Looks like this when cold.
Thanks Dwayne.

Andre The Giant

Thank you Bertrand, I am about to do this on mine, just waiting for parts.

Tom in Austin

Here's what mine looks like ... appears it's correct with the rear disc of the t'stat standing a few mm away from the seal ...

Bertrand Daoust

You're welcome André.
Did you order both front (999.701.632.40) and back (928.106.163.00) seals with the new thermostat?

Tom, looks perfect to me too.

Andre The Giant

I left it in Rogers (GOD) hands.
1 Thermostat 83C Wahler
1 999 701 632 40 Thermostat O ring
1 928 106 163 00 Thermostat Housing Rear Inner Seal 84-95

Bertrand Daoust

Andre The Giant

I thought you might like that Bertrand !

What I wrote in my last post was from his quote.