Notices
928 Forum 1978-1995
Sponsored by:
Sponsored by: 928 Specialists

Tips for Removing Coolant Cross Over?

Thread Tools
 
Search this Thread
 
Old 03-05-2009 | 08:39 PM
  #1  
Glen McCartney's Avatar
Glen McCartney
Thread Starter
Rennlist Member
 
Joined: Feb 2002
Posts: 1,235
Likes: 36
From: Allentown, PA
Default Tips for Removing Coolant Cross Over?

Trying to finish up the winter projects and another problem popped up. There is coolant around the base of the coolant bridge where it goes into the block, guess it didn't like sitting around without coolant for a while when I was changing the water pump and the o-ring dried up.

So, any tips? Does the oil filler neck have to come off, not much room between the bridge and the oil fill neck.

Thanks
Old 03-05-2009 | 08:42 PM
  #2  
the flyin' scotsman's Avatar
the flyin' scotsman
Rennlist Member
 
Joined: Oct 2004
Posts: 10,710
Likes: 53
From: Southern Alberta, Canada
Default

Not sure about the '85 MY but I have the bridge off my engine and the oil filler neck is in place.

I'll get the pic:

Old 03-05-2009 | 08:52 PM
  #3  
928worldwide's Avatar
928worldwide
Banned
 
Joined: Jan 2009
Posts: 362
Likes: 0
From: Philadelphia
Default

Glenn,

Load the thing with sealant and stick it back in- new o ring or not... I always use sealant there.

Old 03-05-2009 | 09:06 PM
  #4  
davek9's Avatar
davek9
Rennlist Member
 
Joined: Jul 2006
Posts: 5,198
Likes: 396
From: Bloomfield, MI
Default

Yes it does two bolts and a few hoses, a great time to re-seal the Oil filler neck.
Edit: I would (and did ) use sealant on the Neck to block, but not on a new "O" ring,
Attached Images  
Old 03-05-2009 | 10:49 PM
  #5  
Glen McCartney's Avatar
Glen McCartney
Thread Starter
Rennlist Member
 
Joined: Feb 2002
Posts: 1,235
Likes: 36
From: Allentown, PA
Default

Thanks, I thought it would have to come out. Just had it out in '05 when I refinished the intake.
Old 03-05-2009 | 10:54 PM
  #6  
jthwan22's Avatar
jthwan22
Addict
Rennlist Member
 
Joined: Nov 2007
Posts: 553
Likes: 0
From: Somerset, NJ
Default

some of the bolt are different length. Make sure you check it.
Old 03-06-2009 | 12:17 AM
  #7  
WICruiser's Avatar
WICruiser
Burning Brakes
 
Joined: May 2005
Posts: 1,007
Likes: 9
From: Chilton Wisconsin
Default

Check the hoses first.

I thought mine was leaking there also but upon further review one of the smaller hoses right above it was leaking and the coolant was puddling in the bridge to block conection area. You have to take the hoses off anyway so check them out because it may save a lot of hassle.
Old 03-06-2009 | 12:41 AM
  #8  
SeanR's Avatar
SeanR
Rennlist Member
 
Joined: Apr 2006
Posts: 35,700
Likes: 501
Default

Just pulled one out of a '90 GT and reinstalled it a few minutes ago.

Easy to do. Wish I had take a couple of pictures. There are two (red) seals that go on each side of the bridge. Replace and add a bit of sealant. The one in the middle is large and requires a bit of pressure to get it in to slide in the block housing. If you are that far in, make sure you pull the thermostat and change the TWO that are there, the larger o-ring that holds the t-stat in place and the rusted one at the rear.

Here is a pic of the rear one, this one is a steel seal surrounded by rubber and is a known failure point. Replace them all and you will be good. I only use sealant on the two on the head bridge points.
Attached Images  
Old 03-06-2009 | 09:43 AM
  #9  
Glen McCartney's Avatar
Glen McCartney
Thread Starter
Rennlist Member
 
Joined: Feb 2002
Posts: 1,235
Likes: 36
From: Allentown, PA
Default

Roger, good point, will double check the hoses first.
Sean, thanks for the picture. I was planning in replacing the thermostat and the seal behind it while I was in there. From the look of the O ring and depth, I may be able to sneak out the bridge without removing the fill neck, I'll give it a try first, of course that is if the hoses aren't causing the leak
Old 03-06-2009 | 10:57 AM
  #10  
Tom in Austin's Avatar
Tom in Austin
Rennlist Member
 
Joined: Jul 2002
Posts: 3,269
Likes: 5
From: Deep in the Heart of Texas!
Default

Check the search, I think Dwayne did an illustrated tutorial on removing the bridge.
Old 03-06-2009 | 11:21 AM
  #11  
Mike Frye's Avatar
Mike Frye
Craic Head
Lifetime Rennlist
Member
 
Joined: Sep 2006
Posts: 8,795
Likes: 6
From: Jersey Shore, USA
Default

Also, be VERY careful with the four bolts if you haven't had the bridge off yet. Since there's leakage there, you may have corrosion. The allen head bolts are prone to stripping out.

I replaced mine with hex-heads, and some anti-seize. Also chase out the threads before reinstalling.
Old 03-06-2009 | 11:44 AM
  #12  
the flyin' scotsman's Avatar
the flyin' scotsman
Rennlist Member
 
Joined: Oct 2004
Posts: 10,710
Likes: 53
From: Southern Alberta, Canada
Default

Glen.........a pic of the coolant bridge and its components. There are 5 seals to replace; 2 tstat that Sean pointed out, the main O ring between the bridge and block and the 2 smaller red coloured seals for the cyl. heads.

Old 03-06-2009 | 12:46 PM
  #13  
Glen McCartney's Avatar
Glen McCartney
Thread Starter
Rennlist Member
 
Joined: Feb 2002
Posts: 1,235
Likes: 36
From: Allentown, PA
Default

Found Dwayne's excellent write up, he does great work a great asset to our community!!!
Thanks for all the tips, nice weekend project.
Old 03-06-2009 | 03:38 PM
  #14  
StratfordShark's Avatar
StratfordShark
Drifting
 
Joined: Sep 2006
Posts: 3,288
Likes: 88
From: Stratford-upon-Avon
Default

I fixed a coolant leak into the well under the bridge by fitting new o-ring and new red gaskets (silicone sealant on the red ones).

All was good but sometime later I started getting a leak which would show up as small trail under car (my trays are off just now) after it had stood overnight after a run. Source was in vicinity of front of engine so I suspected water pump at first.

Turned out it was the hoses. When they get older they can reach point where you have to tighten them more when they are hot.

So check the hoses but if you are getting coolant into the wells under the bridge much more likely to be those gaskets/o-ring.
Old 03-06-2009 | 03:46 PM
  #15  
Glen McCartney's Avatar
Glen McCartney
Thread Starter
Rennlist Member
 
Joined: Feb 2002
Posts: 1,235
Likes: 36
From: Allentown, PA
Default

Just took the hoses off, they were not the leak, it is definitely from the O ring. Taking bridge off now, replacing all the gaskets/orings/t-stat and seal.


Quick Reply: Tips for Removing Coolant Cross Over?



All times are GMT -3. The time now is 01:32 AM.