Small world Dr Dave.  I used to live in Almaden Valley, now I live over at Silver Creek.  Would enjoy hooking up one of these days.  What are you driving?

 

BTW... think i have solved most of my hydro issues with TLC and a careful rebuild.  Car is all level now.  Need to replace some bushings and then tackle the air in the system.   Would you have John's email or a way I can connect with him?  I will register at MOASF and see if i can reach him that way.

 

Cheers

Marc

 

Thanks for all the help... I have one side now working but my real problem is the RH side. The displacer rubber is so deformed it wont push down on the knuckle vertically,   its pushes it at 45 degrees.   Think I need another displacer.  Anyone know of any going?

The answer to the original question is that it acts like any hydraulic system with air in it: no resistance to motion until the air is thoroughly dissolved, and then, depending on how much air there is, it can range from mild softening of the suspension to complete lack of resistance to motion.

Think of how brakes act when you get air in them and need to pump them up.

Hi Mark, I saw your car on Almaden Expressway about a week ago. Welcome to the forum. John Becker with MOASF has a factory pump and should have the correct fluid. Are ypu using the original upper suspension arms or were they replaced? There is a difference between wet and dry arms. You sounds like a valving problem between for and aft. John Becker (in Concord) is very familiar with hydro settups.

dr dave

Thanks for all the thoughts, big help as I want to try and keep the car as a wet car.  I have no leaks and I can get the front up off bump stops but it puts the rear up so high it looks like a monster truck setup. I also have air in system, had to changed the Schrader valves , seems I also lost some front height  after that, assuming air causes saggin too and air sits in front bags.

 

Looking at my car... i notice the knuckle leans back up into the displacer... is this correct.  They dont stand upright? 

See pictures

 

 

 

 

 

 

Also could be that the nylon cups for the front knuckles may have collapsed and broken through, causing the front end to droop.

If all systems are in good shape, you might do as I did years ago, and shorten the rear struts a hair. Having a 5:1 ratio; shortening the rear struts 1/8" will resulted in a 5/8" drop at the rear. I lowered mine by 1.25" by trimming 1/4" from the struts. As a result, the car sits level.

Could be the helper springs, yes.
Also could be the front bags' rubber cones (yes, they incorporate a rubber cone, with an integral `bag' below) have settled more than the rears over time, due to weight.
This can be helped by putting a washer (max 5mm thick) between the front knuckle pin and the strut.

Note thay hydro cars were slightly higher at the back than the front, when new.

[edit] My car now sits level, because some years ago I replaced the complete front subframe + brakes, engine & gearbox with a Cooper S one.
The 1970 S bags in front and stock 1970 `Matic bags in rear = sits level. I'm still running the stock late (orange) rear helper springs.

Weak or incorrect helper springs.

 

Post on moasf.com. There are a few members with pumps. 

Hi All....  

Been searching the forum for answers to my question… "what are the symptoms if air is in the Hydrolastic suspension ?”     My car has no leaks but i think it has air contamination,  I can pump the suspension up but the rear is 50% higher than the front always. Any thoughts?  I have released fluid and pumped up several times via the grease gun pump method. 

 

Any wisdom appreciated ...  I have a stock 1968 Morris Cooper S

 

BTW , anyone know of a shop pump in the bay area (California)   ? One with Vacum and fluid refill ?