dual thermostat installation

[Craig M]

I know this sounds pretty lame, but am having trouble reinstalling the thermostat housing. I have the new style dual thermostat housing on an older 6.5. Put new rubber rings on the new 180 degree Robertshaw's (just like the removed ones had). The area is real tight so just had room to install the new thermostats. Cannot get the bottom 2 bolts to seal correctly. Suspect the thermostat is "rolling" a little while I try to push the loose piece of the housing tight to the fixed piece. Spent a bunch of time Sunday putting it on and off but still not a water tight seal on the housing. Tips?

[john8662]

Make sure you have the correct size gaskets. There are different thickneses available at the auto parts store. The one listed for the 6.5 wasn't in their box, but felpro does have a number for the correct one.

I see your dilemma though!

Any tips guys?

[BILLYDIESEL]

There Is A Chance The Aluminium Housing Could Be Warped.
Make Sur Is Nice And Straight

[HammerWerf]

Craig,

On my '80's trucks, I used just a tiny dot or smear of blue RTV to hold the thermostat inplace while putting the outlet back on. So far, no problems. Never did understand why they designed the outlet with the thermostat verticle.

HammerWerf

[NH2112]

Never did understand why they designed the outlet with the thermostat verticle.

HammerWerf

Probably the same reason they designed the engine so you can't just R&R the water pump in 15 minutes like you can with a 350, 318, IH V8, etc.

[Craig M]

There is a Feltpro number for the gasket? I went to 4 auto parts stores (including Napa regional warehouse), before I found one gasket (and they only had one). I reused one old rubber and one new rubber gasket. If there are different thickness gaskets that might help. I hate putting any sealer on an item in the coolant system, do not want "stuff" running around in the coolant pasages and getting stuck. Something tacky, to keep it in place prior to installing the loose piece is probably right though