Slow Riser!

Hi all!
Have searched the forum and found lots of posts,but a bit lost as to mine..
Ive a P38 that the suspension has always raised and lowered quickly..
Over the last 2-3 weeks its taking forever to raise from Access to Normal (Access light on and Normal flashing) and up higher..
Today (just in case) i replaced the seal in the compressor and its still the same..Car dosent drop over night or lean?
The Compressor runs then stops after a few minutes,then restarts intermitedly so im guessing its reaching pressure ok..
Cant hear no leaks and as i say it dosent drop if left in normal mode...
Im getting no messages on dash either..Just taking 5 mins to raise..
Anyone any suggestions as to where to start looking?
Cheers all
LTel

Boydonegood said:

Hi all!
Have searched the forum and found lots of posts,but a bit lost as to mine..
Ive a P38 that the suspension has always raised and lowered quickly..
Over the last 2-3 weeks its taking forever to raise from Access to Normal (Access light on and Normal flashing) and up higher..
Today (just in case) i replaced the seal in the compressor and its still the same..Car dosent drop over night or lean?
The Compressor runs then stops after a few minutes,then restarts intermitedly so im guessing its reaching pressure ok..
Cant hear no leaks and as i say it dosent drop if left in normal mode...
Im getting no messages on dash either..Just taking 5 mins to raise..
Anyone any suggestions as to where to start looking?
Cheers all
LTel

Click to expand...

When you replaced the seal what instructions did you follow?? Where did the seal come from?? Are you sure you replaced it correctly?? Taking a long time to rise is usually due to no air in the tank which means a worn compressor seal.

When you replaced the seal did you then put everything back together and then try and raise the vehicle right away?? You should put everything back together and make sure all connections are tight and then once you are sure everything is back together properly start the car and leave the door open. Wait until the compressor stops running and THEN ask the vehicle to raise.

If the vehicle is slow to rise then then there is obviously a problem somewhere else. Check all the air bags/springs for any signs of leaks - Just because it doesnt leak in normal mode doesnt mean all the bags are ok, you might have a leak that appears when in access mode but then seals itself as it goes to normal mode - this is caused because when you change down heights the bag folds in on itself and you could open up a crack on the airbag, so, when you try and raise back up the crack could be allowing air to escape. When were the bags last replaced?? Get under the vehicle with a squeezy bottle of soapy water and spray it on the bags and look for bubbles, if you see any then replace the bags.

Let us know how you get on

-Wills

Thanks for the quick reply!! Appreciate it!!
Brought the seal kit from company called P38 spares on Ebay.Followed instructions and all went well.Simple enougth,have replaced a few seals on hydrolic rams before,so know the basics.
Ive let it run for around 15 mins and then tried to raise it,and it still seems very slow..Back end starts to lift quite quick but seems to run out of air as the front starts to lift...
When i take the filter off the input side,and put my finger over the hole i was expecting it to suck hard against skin,but dosent seem much pressure there at all?..But pump seems to be making pressure ok and shuts off after a few mins...
Once run and the pump stops,(im guessing tank full) should that be enougth to lift whole car? or does it rely on the pump to catch up to complete the lift?
Will climb under it with some soapy water as you say.....
Fingers crossed i havent got a bag gone...Its got 150K on clock and although ive only had it about 8 mnths and got loadsa old bills,i dont recall one for susp bags,,so maybe never changed...
Thanks Wills
Regards LTel

If when you leave a door open and the pump is running then switches off,there should be easily enough air to lift the car.If its slow then either the pressure switch is cutting out early or there is a valve block fault.It is also possible,but unlikely that the compressor is overheating.
It really wants a pressure gauge teeing into the tank line to see what actual pressure you are getting up to.The pressure switch should stop the compressor at about 140psi,anything over about 80psi will lift the car slowly.The pressure switch,(the 2 red wires from the green switch screwed into the bottom of the valve block) contacts close at 140 so you can do a basic continuity test there.Beyond that its a Testbook session really.

Cheers Eightinavee
Have had another look today and it seems...
Start the car up on low access mode...When the compressor stops,push the "Normal height" button and the back end starts raising fast by the time the front begins to move,it runs outta air and then the pump kicks back in.
looks like theres not enougth pressure in tank and its using the pump to lift the final few inches on the front..
What sort of continuity test can i do on the pressure switch.Sorry i know you did explain but im at a bit of a loss at finding it and the 2 red wires?
If i drive off with the access light on and the Normal light flashing,am i gonna get any problems? Im not getting the "Slow " message on the dash,but am conserned that at access level im gonna rip a bump stop out or something!.

Thanks for any help..and your time
Appreciate it.LTel

Are you leaving a door open while the compressor is running ? This stops any height changes - which will stop the compressor.From access to normal height will use enough air to make the compressor come back on,but with a full tank it should be able to get the car to height in a few seconds.It does sound like the compressor is failing to get the tank full in the first place,mighty be worth having another look at it.Take the cyl head off the comp and look at the new seal,make sure its OK.

Update
Sorry for boring you all again with this post,but its the only problem on my P38 that i still havent solved..
Fitted the new pump seal to no real effect...Was so confident in the fact i had fitted it properly that i hadnt listened properly to what i was told/advised from off here! Sorry! I was wrong!!
After the situation of the Range taking forever to rise,i finally removed the pump head,and the seal was not well fitting..
Anyway..ive reset seal and the suspention rises in a few mins or so everytime you start (or quicker if cars in use)...So alot happier!
Problem im having is it seems that as soon as the pump has filled the suspention,it cuts out.


I cant find any leaks...and the susp will stay up over night...It just seems im using the pump to raise the car.Lower it when i stop and when i return a few hours later i have to wait for the pump to run a few mins to raise car again? No air tank reserve is being made..
Ive got another P38,,i can rob and swap bits from...Can any suggest where to start?
Sorry for the long post,but things getting a pain now....
Cheers all
LTel

I'm assuming you changed the 'yellow' piston seal, did you check the liner for any scratches/scrapes, this teflon seal is very easy to damage, also you should have changed the mating o-ring that the liner mates against in the cylinder head, there is also a check valve o-ring under the the lid you first remove for access

Hi Tervueren
Thanks for the reply..Yeah i fitted the whole kit (Teflon Seal,and the two O rings) and the cylinder was in good nick...After living with its poor performance for the last 6 weeks,ive restriped it and there is a fine scratch in the cylinder and the Teflon seal was only really sealing properly 1 side..
I repositioned it(best i can) and its a little better,Am just gonna order the piston and seals off Ebay (the £90 one) Hopein it comes assembled!
What it seems like is that i cannot find any leaks...But the compressor only seems to make enougth air to lift the car,( 2-3 mins) and then shuts off..So if you lower it back down again,then attempt to raise it,the pump has to kick back in and run for the 2-3 mins again...
Suspention stays raised all night without dropping.So was wondering if a shut off valve exsists?
Cheers LTel

These may help
rangie.com - The Range Rover Knowledge Base - by Matthew Reeve - Sponsored by bigyellowdesign

P38A Suspension - RangieWiki The Range Rover Wiki

Thanks for that Tervueren
Makes for interesting reading,,and gives me an idea of what to look for next...
Have just fitted the new Piston,Cylinder and seal...The flange "skirt" of this seal is alot thicker than the previous one i had brought and fitted...Havent had chance to test as pouring down..
Can any one advise how hot these pumps run? I admit i had just done 100 mile,but the pumps red hot and untouchable..Im hopeing because of the wear on the seal the pump would have been running too long,hence getting hot...?
Cheers LTel

Hi Mine did exactly the same eventually found it was an air bag leak that you could only hear at certain heights also to start didnt go down over night but got worse. new bag of ebay 60 odd quid and took 10 mins to fit now goes up and down quick as a flash.

Mine was the same and it was the pump, if you take your time and look around you can get the bits Range Rover P38 EAS Air Suspension Pump Compressor Kit for around £60 i’m not saying that’s what it is, but if you have a scratch like you say on the inside of it, then i would look at that first, be VERY careful putting it back and don’t mark it in any way, i know it seems extreme but i used a pair of latex gloves and did all the work on a terry towel to minimise any knocks or bumps and scratches, well it worked in the end and its been working fine since

Cheers for all the replies!
Have recently fitted a new pump kit...Cylinder,piston and seal.And its made a big difference.Car now lifts fast again..
I still seem to feel its not building enougth air in the tank before cutting out though..
From lowest setting and pump shut off, it will lift the car to "normal" height in about 20 secs,lower it back down and then attempt to go back up to normal again and theres only enougth air left to lift the rear?
Then the pump kicks back in and takes 3-4 mins to lift the rest of the car?
Sound right?
Cheers all
LTel

No it still dosn't seem right, i don't know if you can get water in the system or not, and how to clean the thing out, but go here Range Rovers and check it out more and see what you can find in the way of help, tell us how your getting on though ok?