News:

Due to a technical issue, some recently uploaded pictures have been lost. We are investigating why this happened but the issue has been resolved so that future uploads should be safe.  You can also Modify your post (MORE...) and re-upload the pictures in your post.

Main Menu

1968 Eldorado

Started by weephee, December 26, 2009, 11:27:14 AM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

weephee

Hello, I am new to this site.   I have always been a cadillac owner but now I'm venturing into older cadillacs.   I have been looking at a 1968 Eldorado from the south.   The seller send me some pictures of the engine compartment and I noticed that a rather large oblong gold coloured tank on the left fender brace is missing.   I've looked a pictures of 1967 to 1970 engines and the tank is in the pictures.  Can anyone tell me what this is for and how hard it would be to get a replacement.   Thanks  Larry
Larry McPhee

okccadman

That is teh compressor for the level ride system.
Jim Jordan CLC# 5374
Oklahoma City, OK

55 Series 62 Sedan
56 Series 62 Coupe
56 Fleetwood 75 Derham Limo
59 Fleetwood Sixty Special
66 Fleetwood Brougham
66 Superior Hearse/Ambulance
67 Fleetwood Sixty Special
68 Fleetwood Eldorado
76 Coupe de Ville d'Elegance
90 Brougham
92 Fleetwood Coupe
93 Allante
94 Fleetwood Brougham
02 Eldorado Commemorative Edition

weephee

Thanks, so I guess I can assume that if it's missing the air ride system has been converted to regular shocks    Not what I wanted to hear but thanks anyways
Larry McPhee

Glen

Not necessarily. The compressor is not something well understood by the general mechanic so when it fails they have no idea as to how to fix it.  So they recommend that the compressor be removed and the shocks are then inflated manually with an air hose at the service station. 

If the super lift shocks have been removed then helper springs need to be added or custom made leaf springs are installed. 

Stock springs without the superlift shocks will cause the tail end to be low and will affect the handling of the car. 

Glen
Glen Houlton CLC #727 
CLCMRC benefactor #104

Larry McPhee

Thanks  Glen.     Just a follow up question.   Apparently the air tank/compressor is in the trunk.   Is it difficult to find replacement shocks and compressor if necessary and are these parts normally expensive.   If I decide to buy this car I want to restore it to original condition.  Can these compressors be repaired ie. are parts available.   Thanks for your help

TJ Hopland

There have been threads here talking about repairs on the compressors.  Parts do not appear to be commonly available.  I have manual fill aftermarket shocks on my cars and even towing my boat usually dont feel the need to adjust them very often.  My cars are the next (71-78) body style so I dont know if the earlier vintage would be as easy to do that on or not.

Other possible issues on a 68:

First year of 472, nothing unusual except like most Gm's of the era they have the plastic covered cam timing sprocket that do not hold up well with age and mileage.

I have read that the horizontal rear shocks are hard to find (exclusive to 67-70).

I think front disc brakes were still optional but fairly common.  They were a 4 piston fixed caliper.  I have read that parts to support them are getting harder to find.  This design was only an option on 67-68. This vintage also used a different front wheel bearing than the later models which again I have read are getting hard to find.  69-70 used the more common to GM single piston floating calipers that were used 71-78 so they are much easier to find.  I have seen a few 67-68's that were converted to the later discs using 69-70 parts.  I guess the wear parts are the same as the later cars but the control arms and knuckles are exclusive to the earlier style so for a swap you need a 69-70 eldo or toro.

Rest of the mechanicals so far are still around and as you would expect body and interior is nos or salvage.

Nothing that should be a deal breaker, just more information.   
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason

Glen

Larry, the compressors are no longer made and the company (Hadley) does not support them any more.  It seems like the manufacturer does not even remember making them. 

But you can do repairs on the compressor; most of the problems are fixed with a little cleaning.  However it seems some of the diaphragms were made of a material that gets brittle and cracks.  If that happens then you need to find another compressor. 

I would think that new diaphragms could be made easy enough but no one seems to be doing that. 

Glen
Glen Houlton CLC #727 
CLCMRC benefactor #104

weephee

Thank you for all the information.  I talked to the seller again and he says the rear shocks have been replaced with non air ride shocks  so I would need to find replacement rear shocks and likely the tubes.   Just one more question.   Is the tank and compressor a single unit or was the compressor remote from the tank.   From what I can see from the pictures, it looks to me like the compressor is on the firewall end of the tank.   Can someone please confirm this.   Thanks once again
Larry McPhee

TJ Hopland

The compressor is an integral part of the tank.

These compressors were vacuum powered.  By this vintage they ran off the PCV line.  77 or 78 they went to a electric one with a much smaller tank.   The electric ones had a electric sensor on the axle and a control box that ran the compressor as needed or opened a vent.   On the vacuum ones the compressor 'ran' all the time, or at least till the tank was full. The level was controlled by a mechanical valve connected to the axle.  It either let air from the compressor into the shocks or vented them.  I never played with a working one, I assume they just had tiny openings in the valve to keep it from oscillating.   
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason

Glen

TJ is correct, the compressor and tank are one unit.  It should also have the regulator on top.  The regulator should have a yellow cap on it. 

I recommend you do not fill the tank with the manual fill valve until you cleaned the regulator. 

The control valve connected to the rear axle has a damper fluid in it so it does not vent/inflate as the car goes over bumps in the road.  The valves are Schrader valves.  One of the three valves acts as a retainer to prevent the shocks from completely deflating.  Normally the only thing that goes bad with the control valve is it looses the damper fluid. 

Glen
Glen Houlton CLC #727 
CLCMRC benefactor #104