57 Brougham air suspension

[Roger Zimmermann]

Since I have this car, it's never annoying: the air suspension is all too often a source of work. Many years ago when I got new diaphragms from a dentist in Canada (Roger Eickmeier), the car's front was usually down after one day. No matter what I did, there was no change. However, the rear was up for a very long time. Some years ago, the rear went down, especially during cold weather. I went under the car very often with a rattle can of soap water in the hope to find bubbles. I never saw one, nothing, nada.
Last year, I revised the lockout solenoid with a kit from Mastermind. As usual, that kit was expensive but it had the merit to explain where are going the various springs in that solenoid.
Indeed, the front stayed up longer, but not the rear. I suspected that the culprit was a rear diaphragm I installed some years ago after I saw that one from Eickmeier began to deteriorate. I still had one from Mastermind for the rear, but I could not install it due to a manufacturing issue. Therefore, I used an original one. I suspected that this diaphragm may be good in the testing tool but not when installed in the car.
As you may remember, I'm trying to sell the car, but if ever somebody would like to buy it, I would feel bad with that suspension not holding the air. Some weeks ago, it was unusually mild and I could remove the maybe bad air spring assembly and the leveling valves.
I put again the air spring assembly in the testing tool. I'm pumping it to 7 bar and, after one week, I still have 6.7 bar. Obviously, the rapid air loss at the rear is not from that spring assembly. I decided to order by Mastermind a repair kit for rear each leveling valve from the rear. For an unknown reason, the shipment stayed 10 days at the Zurich airport and was delivered finally yesterday.
After reading the very detailed procedure to restore that leveling valve, I decided to use only the needle valves in the RH valve and not go to the procedure to modify the seals at the rotating lever. Why? Because I did almost the same more than 30 years ago!
When new, if I recall correctly, the rotating lever went thru something like a rubber hose. When I restored the car, I removed that questionable system and did one of my own: I slide a brass tube over the shaft, using glue to do it air tight. 3 grooves were provided at the tube for O rings.
At the valve body, I inserted a steel tube into the original one, also glued. To avoid that the assembly went out, I did a small retaining cover attached to the brass tube with 3 very small screws.
The Rizzuto system is a bit different: the original steel tube must be removed from the leveling valve, replaced with a brass tube. The original shaft must be discarded and is replaced by another one with grooves for 3 O rings. To avoid that the assembly is going out, a screw is added at the inner end of the shaft. I could not do that on the original one because that shaft is hardened steel. 
Oh, by the way, do you know what that kit is costing? Only $ 285.00! The only valuable part from the kit is that shaft with the knurled ends. 3 needle valves are identical with the ones for a tire but the 4th one is very special as it's working by pulling its shaft. Indeed, I'm buying this 4th needle valve for $ 285.00; all the other parts were on stock in my garage!
By removing this really special needle valve, I saw that the rubber seal was gone. Indeed the seal was OVER that valve! It could be that I found the air loss.
The future will tell it!

Now, some explanation to the pictures. The first one is showing the leveling valves with the inner parts removed.  Those who are familiar with Broughams will note that at the end of the outside lever, there is a ball joint. I had twice a bad surprise with the original system; this is the reason of the modification; I will explain later what happened. You can also see the tube over the shaft with the 3 O rings.

Second picture: You can see the 4 needle valves and, near the special one, a remain of the seal. At the right of the picture, the retaining cover and 3 small screws.

Third picture: the Mastermind kit. All that for only $ 285.00!

Fourth picture: a comparison between one of the 3 Mastermind valve: the gold one at the left, but it's not gold and a regular tire needle valve. Do you see a difference next to the color?

I will assemble the new needle valves and the other parts and will test the leveling valve. If OK, I will go to the other one; this will be another report and a story.

[carguyblack]

Roger,
Good luck with this project. You sound just like me - hate to have something not working properly even though it really doesn't effect your life greatly! Also, no wonder these kits cost so much. It's not like this car is a 57 Chevy where everything is reproduced already. I think yours is the only car out there on the road and maybe one other parts car in a bone yard somewhere. Joking, but it is a rare bird. Eager to hear if you found the culprit and fixed it.
Chuck

[Roger Zimmermann]

Thanks Chuck! I will report here the good or bad news!

In between, I had a look at the special needle valve from the other leveling valve. It's looking strange to me, like I did myself that extension: it's glued on the needle; I unfortunately don't remember what I did more than 30 years ago. Retrospectively, it should not be too difficult to modify one of the standard needle valve by turning an extension and attaching is securely to the needle.
On the left, the Mastermind needle, the strange one on the right.

[Roger Zimmermann]

To make things more understandable, I did a picture with the shaft and lever into the leveling valve and the retaining cover. The special needle valve is installed too.
The black rubber seal I found was not from this needle valve: I found the transparent seal into the bore. The air leak is therefore not coming from here.

[savemy67]

Hello Roger,

I am not familiar with the air leveling systems used on Cadillac, but I have to think that conceptually they cannot be too complex - compress air, inflate bellows, use check valve to keep air in bellows, use calibrated valving so bellows don't explode.

By the time your Brougham was manufactured, GM had decades of experience with calibrated components used in transmissions, carburetors, distributors, etc.

$285 seems expensive for a modified Schrader valve.

There is a fellow in Germany who appears to be capable of machining just about anything.  His name is Stefan Gotteswinter.  You can find his machining videos on YouTube, and there are Google links to get to his FAQ page and email address (below).

Keep up the good work.

Christopher Winter

http://www.gtwr.de/
http://www.gtwr.de/faq.html

[gouldsom]

I have a Biarritz with air suspension. Many years ago I got three levelling kits from Mastermind, One hundred and fifty dollars each. That was a lot of money as our New Zealand dollar was only worth 45 cents US then. What did I get for my 150 ?. Two tire valves, a gasket, some replacement screws and some instructions. I was p****d off, I only ended up using the gasket. The real fault was the worn shaft and die cast body of the valves, my clever toolmaker friend machined a brass, self lubing bush for the shaft and the system was great. Car used to stay up so well I even forgot it had air suspension. lately it has begun to leak at the back, but I am not worried about that at the moment as I am just entering a massive super restoration of the car, and that is the least of my worries. 
Even I wonder if it would be better converted to springs, but most of the converted cars I see never seem to "sit right", always look too high it the back. When it is working right, it is like a flying carpet, and being able to raise the car, so the rear end doesn't scrape is magic. I think anything I would do to it would be to update the bags and, valves, if it ever came to that stage.

[Roger Zimmermann]

@ Christopher: Indeed , an air suspension is basically what you wrote. It depends on the hardware to have a marginal system or a good one. When the Brougham was developed, GM had already experience with air suspension on bus. Unfortunately, the system at the Brougham was underdeveloped or cheaply made. The regular models build between 1958 and 1960 had a different system, but the reliability was not better. A weak point was at the diaphragms and the lack of positive sealing. With the time and some clever people, some improvements were done. A fellow in Germany is reproducing now the front diaphragms after 2 or 3 years frustrating work and most probably a lot of money.
Vehicles which are now offered with air suspension are much better engineered than was was available or possible in the fifties.. Anyway, such systems are more complex than steel springs.
The man in Germany is certainly something special; I dare to pretend that I don't have 2 left hands, especially when the parts to be machined are small. Look at the picture, this is 1:12 scale! Maybe the image will be removed as it's obviously not a Cadillac!

@ Richard: The air suspension from your car is completely different than the one from the Brougham. I may understand your frustration about Mastermind! I spent already a lot of money to this company; sometimes the price is justified, sometimes not at all. I have the luck to be able to do a lot myself so I don't get fooled my unrealistic promises. Sometimes however, I bite the bullet like the kit for those leveling valves.
Good luck with your restoration project!

[Roger Zimmermann]

I decided not to modify the axle shaft if there is no air leak. I assembled the first leveling valve and scratching my head about the second one on the driver side because this is the one which gave me trouble twice. The first trouble was the day I should have go to the inspection to license the car. I was driving when I noticed that the car was leaning to the left. I barely made my way to the GM dealer. They took the car on a lift; I saw then that the shaft was hanging at the outside lever. Logically, all the air from that spring went out. I removed the valve, went home with a loan car, repaired the leveling valve (I don't remember if the home made retaining cover attached with the 3 small screws was already done or if I did that modification that day). I went back to the dealer, installed the leveling valve and went away.
Years later, I had the same break down on a freeway, en route to a club meet. I pulled on a rest place and I had some luck as there was a man from a road assistance repairing another vehicle. When he was ready, he came to my car. I had to use the bumper jack to lift the rear until he could use his hydraulic jack. He removed the valve, disconnected the shaft and lever from the suspension arm and we had outside the car 2 parts...I opened the leveling valve, inserted the shaft at the correct location. The home made retainer was still there, the tiny screws too, but the threads were no more good. By just installing the valve that way, it was evident that after one mile the shaft would come out again. What to do in such a situation? We just peened the knurled shaft locking the retainer, thus preventing the shaft to get out.
The man reassembled the whole (he had the tools and I had not the proper cloth for that work) back on the car and he left. I let run the engine a while to inflate the suspension and after a while we went to our destination with a mixed feeling.
Later, I wanted to drill the shaft to put a larger screw and I realized then that the shaft is tempered; therefore, I took no further action.
The big question I had the last few days was: should I grind the peened shaft to be able to take the shaft out and do the modification from the kit or leave it as is? I took the gamble to assemble that valve as is. If it's leaking, then I do the modification. If not, I'll leaving it as is.
Yesterday, I went to my garage to check the valves. The one with the peened shaft is OK, the other one has a massive leak at the cover! No wonder: by tightening too much the 4 screws, the cover got out of shape. I will correct that with the best tool available: a hammer. Is that the reason why the rear lost its air? I don't know yet. The fact is that I never used the soap water at the cover.
Now, why the shaft from that valve went twice out? It's rathe easy to understand: the leveling valve's arm is connected with a rod to the lower suspension arm. The connection is done with rubber grommets and is relatively unflexible. The up and down movement from the suspension had a pulling action on the shaft which can be probably corrected by bending the arm or rod the right way. To avoid this, I installed a ball joint at the arm and at the suspension lever to avoid this problem. The other side had probably the contrary: a pushing action.
I'm attaching a picture from the leveling valve with the peened shaft.

[J. Gomez]

Roger,

Just a wild guess since I’m not familiar with this particular part, and not sure how much space there may be around the shaft and with the cover ion place. 

But can the shaft be drilled and tapped to place a screw in place with a flat washer to hold it in place (see my Picasso drawing on your picture  ) and add a pin between the washer and lever to help locking everything in place.

The screw can be removed if there is a need to redo the unit at a later time.   

[Roger Zimmermann]

No, because, as I wrote, the shaft is hardened. It may be possible to drill an hardened part, I cannot do that.
Your idea with the screw is exactly what Mastermind is doing on the shafts he is selling; of course before hardening.

[Roger Zimmermann]

Last week, I tested both leveling valves; after some massage, the deformed cover was straighter and both valves were air tight. Everything was assembled again, and I left the garage with the car at normal level. The day after, big deception: the back was down. Obviously, something is not good. I decided to disconnect the LH air spring by plugging the pressure outlet at the corresponding leveling valve and adding a block of wood between the rear axle and the frame.
Today, I went to see the result by jacking the rear axle. I had the pleasure to see that the RH air spring was tight as the rear went up, supported on one side by the wood block and by the air spring the other side.
I removed the LH air spring assembly and I saw that I had spacers between the dome and retainer. If I remember well, a certain distance between to of diaphragm and dome was indicated. To comply with that, the added spacer allowed for a time to have a good seal between the rubber and the dome. With the time, the pressure became insufficient, resulting in an air leak. To be sure about my theory, I put the LH air spring in the testing tool, without the spacers. I will see tomorrow or the day after if the pressure is OK or not.

[Roger Zimmermann]

It seems that my theory was correct. The air spring assembly still had the same pressure after 24 hours. All is installed on the car now; I hope to see the back up next time I'm going to the garage!

[Roger Zimmermann]

It's always great to say: success! Unfortunately, in my case, it's more disappointment after disappointment.
Today, I tempted something different: I removed the LH leveling valve, and put it in water to see if it's air tight, after studying how to do it. No bubbles. Then, I removed the LH air spring assembly, installed in on the test fixture and went to the village's fountain which is not far away. No bubbles! I still don't know why the LH spring assembly is loosing air...

[Glen]

For leak detection I use a mixture of Dawn dish detergent and water.  I either paint it on with an artist brush or spray it on with a trigger spray bottle.  Both methods will produce some bubbles when applying but watch for the bubbles to grow.  Small bubbles mean a small leak, large bubbles, large leak.  The exception is vary large leaks that just blow the solution away.   

[Roger Zimmermann]

In fact, I'm using something similar: a spray can for trucks as they are using compressed air for the brakes. Very useful, but useless to detect a leak at a diaphragm. This is the reason why I dipped the assembly into the fountain!

[savemy67]

Hello Roger,

I just got the most charming mental image of you dipping the spring assembly in the village fountain!  The next time I am in Rome, I will check the idle circuits on my rochester 4GC by dipping it in the Trevi fountain  .

Christopher Winter

[Roger Zimmermann]

A picture would have been welcome, I know! However, that assembly with the test device is heavy (I have to carry it for about 200 meters and then I had wet hands and no camera with me!
I'm not sure if the people in Rome would appreciate that you are blessing your carb in that fountain!

[Roger Zimmermann]

The assembly air spring and leveling valve for the LH side still had the same pressure as for 2 days ago. However, for 2 days, when  tried to see if any bubbles could be seen, I "inflated" the leveling valve at the outlet going to the air spring. To my surprise, the air escaped at the pressure fitting. At first, I did not understand why and put a plug. With that plug, the leveling valve was tight.
Back home, I was more in a mood to think about this strange behavior. The pressure fitting has two 2 tire valves: the inside one is pushed by the lever when the vehicle is too low and the other one should be a check valve preventing the air to go out. Is something wrong at my leveling valve?
Indeed, this check valve was unscrewed and allowed air to escape. Is that the main culprit?
I assembled everything at the car (I'm getting each time quicker!) put air into the system and went home. Tomorrow I will see if this was the solution.
The pictures are showing the tested assembly and a view at the underside of the car. You can see at the differential that I used a number of time the jack to lift the car at the rear!

[Roger Zimmermann]

It seems that I found the culprit! All that unnecessary trouble and expense for just a 10 Cents tire valve! At noon, the car's rear was still up. Now, I can open the driving season!
The picture is not from this year...

[carguyblack]

Great job chasing the problem and great story, too! What a stunningly stately automobile.