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re: Thermostat

Posted: Fri Oct 17, 2008 3:46 pm
by whydahdvr
Is there a metal bracket or clip that holds the thermostat in the housing? If so, where can I find a replacement? I just pulled the thermostat housing off of the top of the engine to replace the thermostat and gasket and discovered a very rusted interior and some sort of metal clip holding the thermostat near the top of the housing rather than seated against the opening like I expected.
Advice?

Posted: Fri Oct 17, 2008 4:10 pm
by OKCM38CDN
It is call a thermostat retainer... it holds the thermostat up inside the outlet...

You can get a replacement from Midwest Military for a couple of bucks...

Hope this helps..

Posted: Fri Oct 17, 2008 4:16 pm
by whydahdvr
Thanks Wes. I explored my manuals again after I wrote this and discovered the retainer item. Should have read that again first. Do you think NAPA might carry one of those? Just because I want to get it done this weekend, but I'll check with Midwest Military or AJP. Thanks.

Posted: Sat Oct 18, 2008 7:55 am
by Cacti_Ken
That is interesting. When I pulled my thermostat housing off the thermostat was on top of the head. So thats where I put it back and the retainer holds it down.

Posted: Sat Oct 18, 2008 8:53 am
by maeserik
In our M38 and my son's GPW we put the modern thermostat 180° type direct on the head and the retainer above it. In both jeeps it works fine, nice constantly temp during winter and summer. We use the 180° thermostat, and the engines runs about max.170 - 190°F, good to have nice and clean oil in the engine. An no sludge at the dipstick, even in short rides.

Erik.

BTW Ken you have nice trailer for your jeep....

Posted: Sat Oct 18, 2008 5:32 pm
by wesk
If you are using the correct thermostat (very large complex looking unit) then the correct installation top to bottom is:
1-Elbow
2-Thermostat
3-Retainer
4-Gasket
5-Head

Image

Posted: Sun Oct 19, 2008 6:19 am
by maeserik
That is right Wes ( as always) , but who still has the original model ?
With the original model, the thermostat feeler is also close to the head to react directly.

Erik

Posted: Sun Oct 19, 2008 10:26 am
by wesk
We certainly have the correct one here. Must be a lack of proper parts in Europe. I can only caution folks against installing the correct thermostat below instead of above the retainer.

I will also suggest that in either case unless the coolant level is too low the adapter neck is always full of coolant and the temperature will be quite the same in the 2" difference in height. I will also remind folks that as the engine is running the coolant pump is directing coolant under pressure at the thermostat assuring it will be immersed in coolant at all times provided coolant remains available in the radiator supply.

Posted: Sun Oct 19, 2008 6:37 pm
by whydahdvr
Looks like I have the original type of thermostat housing. Waiting to get a replacement retainer this week. AJP has NOS thermostats and housings too.

Posted: Sat Oct 25, 2008 7:03 pm
by Cacti_Ken
Wes, I am using a modern automotive type thermostat and it is positioned on top of the head with the retainer holding it in place. Are you saying that you don't recommend installing this type of thermostat that way?

Posted: Sat Oct 25, 2008 9:44 pm
by wesk
Actually I am saying that retainer is for the old style thermostat and it was not designed to properly retain a modern short thermostat tight against the head. It will retain a modern short thermostat tight against the top of the elbow.

As I said above any time the engine is running and there is coolant in it there will be coolant under pressure pushing against either thermostat if it is retained tightly against the top of the elbow. If you do a little testing you may find your retainer sets just a tad recessed in the elbow without a thermostat sitting on top of it.

Posted: Sun Oct 26, 2008 8:08 am
by Cacti_Ken
Ok, thanks for the explaination.