HT4100 4.1, 4.5, 4.9 Discussion, 94 4.9 bypass siezed A/C compressor in Cadillac Engine Technical Discussion; After reading other postings, I tried the suggestion of measureing the belt length needed using string and bypassing the A/C ...
After reading other postings, I tried the suggestion of measureing the belt length needed using string and bypassing the A/C compressor. And so far it is working.
I am using a 62inch (1.6m) belt. Duralast 620k6 or Dayco 6pk1575. The geomitry of the pulleys provide enough contact on the water pump pulley to keep it functioning. Thought I would post my findings since I spent a lot off time trying to find this out. I'm sure I'm not the only Caddy owner out there with this issue.
Have gone through three reman. compressors. They all fail the same way. Will save up my money for a OEM one this time. Or if someone can suggest a reliable vendor for A/C Parts.
Thanks for this, Got me thinking if I should bypass mine now. Need a new serp belt anyway and have already bought one but haven't installed it yet.
I am low on refrigerant so the compressor should be disabled, thinking I may now want a shorter belt to bypass just to make sure it doesn't ever kick back on and seize until I decide what to do with it.
Also makes no sense to spin the compressor when I can never use it.
Bypassing has no effect on anything else right?
And it should be the same on any 4.9 right? specifically a 93.
I know what you mean. The three remans that failed, happend even when the A/C was not in use.
I'm not sure what to tell you about doing what I did for my 94 on a 93. I wasn't able to come up with any definit information what the difference is.
When I was looking for a solution, I was able to find a bypass pulley that replaces the A/C compressor. But for a 93 4.9, not a 94 4.9. I even called the local Cadillac dealer and talk to the parts dept.They had no clue. I know they are not a free information sevice, but when I worked in GM parts dept. We were always happy to help with about any question.Anyway
You could try the above mentioned length. And adjust up or down a inch or two if it's not right. I have not noticed any adverse effects on anything else. Drove 25 miles to work this morning keeping a eye on all the bells and whistles. Everything was peachy kean. If any thing surfaces, I'll post it and notify you.
Nice work - thanks for posting, and with a routing diagram! You're right that this is not an isolated problem, and you've just saved a bunch of guys a bunch of searching for an answer. That's what this site does best.
Yes, thanks for the info! I'm at 136k miles on the original A/C compressor on my '94 Deville, so I'm dreading the nearby day that it fails! It's the only original accesory left. Now I know what belt to have on hand just in case!
Thanks for the post, that routing diagram appears to be the same as my 4.5. My air conditioning hasn't worked since the late 90's, so I've been dreading the day my a/c compressor locks up, honestly I'm surprised it hasn't already.
I think I'm going to give that belt routing/belt a shot and see how it works on mine, I guess the only thing I'm really concerned about is the contact patch on the water pump.
I have driven back and forth to work over a week. Also had car inspected and it passed with flying colors. Still no bad side effects. Seams to be driving water pump, no problem. One thing I can't watch is Temp. There is no gauge in the Inst. Cluster. But milage and performance has been normal. When you have your belt off, turn your water pump pulley by hand. It is very easy to spin it. Thats why I feel that the small contact patch the belt makes is sufficent.
I'll have to look at my manuals to see if there is a difference between the 95 and 94. But on my 94, removing radiator fan did provide some room for working on the compressor. The 94 has just one bolt connecting the hose to the compressor. Will post more later.
Automobile(s): 1991 Sedan deVille 4.9L/1994 Lincoln Town Car 4.6L
Chatham, Ont., Canada
Re: 94 4.9 bypass siezed A/C compressor
I dunno about a 94, but my 91 4.9, the compressor is at the bottom and the lines are held in place by a plate on the back of the compressor, just take the bolts out and the lines come right out. The AC compressor was easier to remove than the alternator is.
Just replaced the belt on my 93, I decided to use the regular size and not bypass the ac compressor at this time.
I did however have to pull this thread up to see the routing diagram, I originally routed it by the placard under the hood and had about 4 inches slack. The hood decal on mine looks to be wrong, they took me the wrong way around the waterpump and ac compressor. Where did this diagram posted come from??? FSM??