Glen McCartney

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

the flyin' scotsman

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:

928worldwide

Glenn,

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

davek9

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,

Glen McCartney

Thanks, I thought it would have to come out. Just had it out in '05 when I refinished the intake.

jthwan22

some of the bolt are different length. Make sure you check it.

WICruiser

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.

SeanR

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.

Glen McCartney

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

Tom in Austin

Check the search, I think Dwayne did an illustrated tutorial on removing the bridge.

Mike Frye

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.

the flyin' scotsman

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.

Glen McCartney

Found Dwayne's excellent write up, he does great work a great asset to our community!!!
Thanks for all the tips, nice weekend project.

StratfordShark

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.

Glen McCartney

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.