P38A Dunlop air springs

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Medway

New Member
Posts
8
Location
Chatham, Kent
Hi, I recently replaced both rear air springs as the ones on were quite perished and leaking air.

After fitting them the OSR would drop overnight and as I couldn't find any leaks with soapy water I bought a valve refurb kit and a length of air pipe in case the problem was elsewhere.

I decided today to try to pump up the air spring on the Range Rover using a short length of new pipe and a tyre compressor and the top mount popped off the air spring

Do I have a faulty air spring ? There is no eveidence of any glue or sealant, the rubber just seems to be a push fit onto the top mount ?

Genuine Dunlops, bought from Island 4X4. Any thoughts ?

Many thanks
Michael
2000 DSE
 
they only use a small amount of lube to pop the piston and top plates onto the diaphragm . Be careful what you use to pop it back on as if it dries or becomes flakie it will get into your system and usually ends up seated on a NRV or solenoid base;)
Sounds like a leaking pipe more than the spring.
 
It should not be possible to displace the bladder. The weight of the car resting on it and the pressure inside it should seal it firmly on the seat. The rear bags on full extension do have a curve in them, the only reason i can think of that a bag fitted to the car would detache is that front shockers have been inadvertently fitted to the rear suspension.
 
I second that ^, unless the car was lowered onto the rear airbag when it was completely empty. It will crease and deform when it's filled with air and can pop off. Ask, go on.... The bag as said just pops back onto the top hat and the weight of the car will maintain a seal. Normally...
 
I second that ^, unless the car was lowered onto the rear airbag when it was completely empty. It will crease and deform when it's filled with air and can pop off. Ask, go on.... The bag as said just pops back onto the top hat and the weight of the car will maintain a seal. Normally...
What Mark says, if you let the car sit on a fully deflated airbag it may well be the cause of your problem, you may need to replace it.
 
Many thanks for your replies.

I fitted the bags about 6 weeks ago using Keith's guide and all was well apart from the OSR slowly lowering. I guessed that there may be a leak in the airline as the exhaust was blowing badly. The exhaust has now been replaced.

The car has been left on axle stands under the chassis with the wheels on the ground so the rear suspension has been left fully extended. Having now bought some airline and a valve block kit, today I thought I would start from the back to try to isolate the problem - testing first the airbag, then the line from the block to the OSR, before refurbishing the valve block.

I managed to get the top seat back on the bag using a smear of red rubber grease but haven't had much success.

I've tried to partially inflate the bag to ease out the folds and have also tried with the chassis partially raised but can't get the bag to inflate enough before it starts to leak at the top and finally pops. The problem seems to be with how the bag is 'folded', if that makes sense. I am putting the top mount in first but will try again tomorrow with putting the bottom mount in first to see if that helps.

I can't remember how the bags were folded before to get them in, do the bags fold inside themselves to be fitted or just get squashed up to fit ?
 
Many thanks for your replies.

I fitted the bags about 6 weeks ago using Keith's guide and all was well apart from the OSR slowly lowering. I guessed that there may be a leak in the airline as the exhaust was blowing badly. The exhaust has now been replaced.

The car has been left on axle stands under the chassis with the wheels on the ground so the rear suspension has been left fully extended. Having now bought some airline and a valve block kit, today I thought I would start from the back to try to isolate the problem - testing first the airbag, then the line from the block to the OSR, before refurbishing the valve block.

I managed to get the top seat back on the bag using a smear of red rubber grease but haven't had much success.

I've tried to partially inflate the bag to ease out the folds and have also tried with the chassis partially raised but can't get the bag to inflate enough before it starts to leak at the top and finally pops. The problem seems to be with how the bag is 'folded', if that makes sense. I am putting the top mount in first but will try again tomorrow with putting the bottom mount in first to see if that helps.

I can't remember how the bags were folded before to get them in, do the bags fold inside themselves to be fitted or just get squashed up to fit ?
The bag should not need to be squashed much as you put it, if the wheel is on the ground and the chassis raised to wade height, put the top of the bag in place and with a little effort the bottom should go in. Trying to inflate the bag if it is not retained at both ends will pop it off, not sure if that is what you are trying to do.
Most likely your leak is in the pipe to the bag if the exhaust was blowing, but leaks where the pipe goes into the bag are not uncommon..
 
I think the gauge only got to about 20 PSI, then pop !

That's not enough to pop a spring. They usually take about 50psi to lift the car. My guess is that either the top wasn't in square or on the **** slightly and the angle caused the bag to come adrift on the side or it was a faulty bag from the start. Once it is off it is game over and time for a new bag.

Did you check the seatings and get rid of all rust before you fitted the new bag?

Given they're made in China I would think dodgy bag is very possible.
 
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