NAXJA Forums -::- North American XJ Association  

Go Back   NAXJA Forums -::- North American XJ Association > NAXJA's Technical Forums > OEM Tech Discussion
Register FAQ Users List Calendar Mark Forums Read
HOME Member FAQ Sponsor Info Rules Donate Bylaws Store Members Chat E-Mail

OEM Tech Discussion Forum for OEM (Original Equipment) or stock XJs and MJs.

Reply
 
Thread Tools Display Modes
  #1  
Old November 2nd, 2009, 16:48
Hylander's Avatar
Hylander Hylander is offline
NAXJA Forum User
 
Join Date: Jul 2009
Location: Texas
Posts: 240
Leaking Thermostat Housing ?

I can't seem to get my TH to stop leaking.
It is leaking through the gasket.
I have replaced it twice, once just last night and today it is still seeping.
I tried Gasket with no RTV, then Gasket with RTV.
Leaks at the same spot each time.
I'm thinking the Housing is warped ?
Reply With Quote
  #2  
Old November 2nd, 2009, 16:53
mattbred's Avatar
mattbred mattbred is offline
NAXJA Forum User
 
Join Date: Apr 2007
Location: Canada
Posts: 753
Re: Leaking Thermostat Housing ?

Positive its the housing and not a hose that goes to it?
Reply With Quote
  #3  
Old November 2nd, 2009, 17:03
5-90's Avatar
5-90 5-90 is offline
NAXJA Forum User
 
Join Date: Mar 2003
Location: Hammerspace
Posts: 18,799
Re: Leaking Thermostat Housing ?

Quote:
Originally Posted by Hylander View Post
I can't seem to get my TH to stop leaking.
It is leaking through the gasket.
I have replaced it twice, once just last night and today it is still seeping.
I tried Gasket with no RTV, then Gasket with RTV.
Leaks at the same spot each time.
I'm thinking the Housing is warped ?
Which spot, specifically, is it leaking from?

If it's coming from somewhere near the base, inspect the mating surface on the cylinder head (pay particular attention to the screw holes) and on the housing. If no defect is visible, get a flat bastard or mill file (or 120-grit sanding sheet stuck to a rigid flat surface) and clean up just enough to get it flat. I'd probably put a coat of machinist's blue dye on the thing before I started cleaning it up - it will show up any unevenness in the surface (as soon as you start sanding/filing) and tell you when to stop. You should only remove enough material to make the surface flat (it is unlikely that you have to do any cleanup work on the head casting.)

Again, pay attention to the screw holes in the housing - check for any cracks between them and the "main chamber" that could be passing water when hot or under pressure.

Make sure you haven't "corroded through" anywhere on the two hose nipples, which could give you a leak from under a hose. Also, you can get a "corrosion channel" on the outside surface that can do much the same thing. In either case, the repair is actually replacement.

Tell us the specific location of the leak on the housing, and you'll get more specific advice.
Reply With Quote
  #4  
Old November 2nd, 2009, 17:05
wishbone's Avatar
wishbone wishbone is offline
NAXJA Forum User
 
Join Date: Feb 2009
Location: Carbondalahara
Posts: 147
Re: Leaking Thermostat Housing ?

just use RTV. I applied 1/4" RTV bead, finger tighten the bolts, but leave some room between the surfaces. I waited 24 hours, then went back and tightened them down, and no more leak.
Reply With Quote
  #5  
Old November 2nd, 2009, 17:31
Hylander's Avatar
Hylander Hylander is offline
NAXJA Forum User
 
Join Date: Jul 2009
Location: Texas
Posts: 240
Re: Leaking Thermostat Housing ?

It is leaking just about 1/4" above the Lower Bolt and
extending up about 1.5" right through the gasket.
I'm thinking I should just order a new Housing, But will try the Flat File
to clean it up.
Reply With Quote
  #6  
Old November 2nd, 2009, 17:45
joe_peters joe_peters is offline
NAXJA Forum User
 
Join Date: Apr 2008
Location: Grants Pass, OryGun
Posts: 13,750
Re: Leaking Thermostat Housing ?

Quote:
Originally Posted by Hylander View Post
It is leaking just about 1/4" above the Lower Bolt and
extending up about 1.5" right through the gasket.
I'm thinking I should just order a new Housing, But will try the Flat File
to clean it up.
Wrap some sandpaper around a piece of 2x4 and hit the gasket surface--that will show you if you have high/low spots.

Getting the mating surfaces clean is a must--bare metal. Check around the bolt holes in the head with your finger and feel if the surface is raised. Use a regular scraper to clean the head of any left-over gasket/sealant.

I'm old school. I use Permatex non-hardening on the t/stat housing, with a couple dabs to anchor the t/stat in the housing, and I never put anything on the head mating surface. You don't want sealant on the head itself where it is so hard to clean up.

Last edited by joe_peters; November 2nd, 2009 at 18:13.
Reply With Quote
  #7  
Old November 2nd, 2009, 18:18
ehall's Avatar
ehall ehall is offline
NAXJA Member
 
Join Date: Dec 2007
Location: Southern Maryland
Posts: 8,768
Re: Leaking Thermostat Housing ?

The housings are aluminum and warp over time. Luckily they are pretty cheap so if you've got some pocket money just replace it.
__________________
.
my '91 beater rebuild
Reply With Quote
  #8  
Old November 2nd, 2009, 20:27
iwannadie's Avatar
iwannadie iwannadie is offline
NAXJA Member
 
Join Date: May 2008
Location: Gilbert, Az
Posts: 2,584
Re: Leaking Thermostat Housing ?

I had the same problem a while back. For me the problem was a small amount of coolant in the head. With the housing off no coolant would drip out but with the housing in place a tiny bit would seep and ruin the gasket/rtv enough that it would then later leak really bad.

I took a fluid pump and got as much of the coolant from the head as possible, solved my problem.
Reply With Quote
  #9  
Old November 2nd, 2009, 20:30
mattbred's Avatar
mattbred mattbred is offline
NAXJA Forum User
 
Join Date: Apr 2007
Location: Canada
Posts: 753
Re: Leaking Thermostat Housing ?

Quote:
Originally Posted by iwannadie View Post
I had the same problem a while back. For me the problem was a small amount of coolant in the head. With the housing off no coolant would drip out but with the housing in place a tiny bit would seep and ruin the gasket/rtv enough that it would then later leak really bad.

I took a fluid pump and got as much of the coolant from the head as possible, solved my problem.

I noticed this when changing my tstat - I sucked some out and jacked the front of the engine up to make the coolant sit back. Problem solved! Need a dry surface.
Reply With Quote
  #10  
Old November 3rd, 2009, 07:25
ChevelleSSLS6's Avatar
ChevelleSSLS6 ChevelleSSLS6 is offline
NAXJA Forum User
 
Join Date: Jan 2007
Location: Grand Rapids, MI
Posts: 498
Re: Leaking Thermostat Housing ?

I cracked the Hesco unit I bought for my XJ earlier this summer, and with a little grinding and JB weld (ghetto I know) it works great now. DO NOT torque the tstat housing down very hard!!!
Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
thermostat housing help!! CBB311 OEM Tech Discussion 10 January 22nd, 2009 21:18
WTB thermostat housing Israel InterMountain Chapter For Sale/Wanted 3 September 9th, 2008 04:51
thermostat housing 4.0L dude in an xj For Sale: Private Party Only. XJ ITEMS ONLY 0 May 30th, 2007 17:24
Fun with the thermostat housing BIGSLVRXJ OEM Tech Discussion 0 January 29th, 2006 18:51
Aftermarket Thermostat housing for 4.0 ? 96 Cherokee Modified Tech Discussion 9 November 11th, 2005 07:38


All times are GMT -7. The time now is 19:52.


Powered by vBulletin® Version 3.8.3
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
NAXJA and NAXJA logo's Copyright NAXJA. All content/images Copyright NAXJA 1999-2014