sinking feeling - front keeps dropping one side

[rudey]

hey all, my lincolns been sat around for a while, again, been too busy to get involved, anyway, the front left ram wont hold the car up, when on full lift within about 5 minutes the rams started dropping as if its not holding pressure?

Is it the ram or something else im missing (i.e. on the pump end??)

[fatdaddy]

if there are no visible leaks at the ram or pipe fittings..........
close the slow down for that corner fully then see if it still drops. if it still drops it is the pump head that is leaking (most likely the small O  ring at the pressure port on the center block)

if it stops dropping with the slow down closed it is the dump that is leaking back to tank.

[rudey]

its plummed side to side, the back dont drop when sat lifted so it must be the pump rerun side then... damnn it lowriders are hardwork!!!

[fatdaddy]

shutting the slow down will confirm it but  sounds like the dump for that corner is leaking.
take out the dump stick and blow the valve end with an air line. look at the small o rings on the end, they can get nicked if the stick is not perfectly square when screwed  in.  swap the sticks around  for more confirmaation

[rudey]

well today was very wierd, took the car to a show and had to keep tweaking the switch every couple of minutes to stop it dropping.... thought ok, ill sort that later, upon me return home, the dropping stopped!! and then began to drop on the other front!! different pump completely... how you explaine that!! left car fully up tonight to see whatr happwns

[fatdaddy]

contamin ation in the oil  ?......................have you tried leaving it with the slow downs shut

[rudey]

when i leave it locked out at full lift the car holds its own, used yesterday and today, sometimes it drops stupid quick (either side) and other times it holds itself... can understand it....

[chewy]

check valves

[fatdaddy]

have you tried the slow downs Rus?

still sounds like contamination floating about to me

[rudey]

have you tried the slow downs Rus?

still sounds like contamination floating about to me

i havent tried slow down valves as the back rams stay up. (as its plumbed side to side) if the slow down vlaves were failing wouldnt the whole side drop not just the front?

im gonna try and strip down the dumps ina bit, still havent got acces regassed yet either (although that shouldnt effect it as they not live at the moment??

[fatdaddy]

your not shutting the slow downs because they are failing, your shutting them to rule out the dump leaking.
if it still drops with them shut the oil MUST be going back through the check valve OR then pump head. Once you've ruled them out/or confirmed them as leaking [by shutting the slow down] the only other way back to tank is through the dump

[for a better explanation see
http://uklows.com/forum/index.php/topic,2291.0.html ]

[rudey]

hey iain, i did waht yiou said last night and raised the car (then i backed it off slightly so it holds it own) then turn the slow down valves off, it does stay up when locked out, when dropped slightly (i.e. pressure off locked out) then it drops, and this morning as expected its sank all round at various levels? what does this suggest then now i need to look at?

[fatdaddy]

so it sank with the slow downs shut ? (i think that's what you said  )

in that case it is a check valve, they really only malfunction if they get crap in them, so you need to flush out the systems well and start again nwith fresh oil (not unknown for US assembled pumps to have swarf in them  )

[rudey]

ok, so are the check valves the joints with the ball bearings in? not the dump connectors? (before i start completely dis-assembling the system)

[fatdaddy]

yes.

C1 in this  http://uklows.com/forum/index.php/topic,2291.msg21146.html#new