Cadillac & LaSalle Club Discussion Forum

Cadillac & LaSalle Club Forums => Technical / Authenticity => Topic started by: Chad "Classic Chevy One" on January 14, 2009, 10:55:16 PM

Title: 85 Eldorado 4.1 Water Pump Problems
Post by: Chad "Classic Chevy One" on January 14, 2009, 10:55:16 PM
Hello all, I am new here and have been tasked to repair my folks 85 Eldorado. I have restored many classics mostly in the muscle care arena. Here my problem; I installed new water pump having problems with the tube which crosses from thermostat housing to manifold. Tube had rust in o-ring areas. Wire brushed tube well, then placed a thin bead of silicone on tube areas where o-rings are placed. Installed o-rings then another thin bead of silicone. Installed pump, thermostat housing and cross tube as one assembly. Leak seams to be coming from manifold lower side of cross tube. I am open to any tips or sugestions.
Question’s I have:
1. Can I remove thermostat housing and tube without pulling the pump again???
2. Should I replace the tube with a new one if one is available from the dealer still? 
Tube dose have some pitting but the silicone should have helped this, maybe I should not use the silicone.
3. Should I try to re-clean the tube, seal again and re-install thermostat housing and tube again?
I am a seasoned mechanic and I have to say this pump assembly is one of the poorest engineering I have ever seen! Silicone i am using is red high temp.
Thanks all,
Title: Re: 85 Eldorado 4.1 Water Pump Problems
Post by: 76eldo on January 15, 2009, 09:02:03 AM
The design is a bit baffling.  As far as the order in which to assemble, a shop manual may help.

Contact the HT4100 forum, there are a lot of experts there that can probably help quickly.  Here's the link:

http://autos.groups.yahoo.com/group/HT4100exchange/ (http://autos.groups.yahoo.com/group/HT4100exchange/)

Good luck,

Brian
Title: Re: 85 Eldorado 4.1 Water Pump Problems
Post by: Walter Youshock on January 15, 2009, 12:22:19 PM
As I recall, there was a clip that went on the tube and forced the "O" rings to seat.  Without the clip, I doubt it'll seal properly.
Title: Re: 85 Eldorado 4.1 Water Pump Problems
Post by: Chad "Classic Chevy One" on January 15, 2009, 01:32:58 PM
You are correct on the clip with a spring and a washer so that the o-ring is supported and pressed into the thermostat housing too, the manifold end of the tube is flanged to support the o-ring.
Do I or is it best to pull the whole pump, thermostat housing and cross-tube again or can I just unbolt the thermostat housing and cross-tube without desturbing the pump and gasket???

Thanks for your replys, 
CP