TD5 rear suspension listing

Hi all the old TD5 disco (2000 model) has a list to the drivers rear every morning fire her up and it lifts after about 1-2 mins but have noticed it going down after only a few hours now. Compressor working fine pipes seem ok need help please on the old idea front.

Probably the rubber balloon leaking. if you spray it with soapy water and observe you will see a white patch appear where it ia pourous. it is a fifteen minute job to change and they are 68 quid each from paddocks. I did one on mine three weeks ago. there has been a lot of threads on this in the past if you do a search....

Excellent and very comprehensive guide Battenberg, I will keep it for future reference.