What pressure do air-jacks run at??

[450Nick]

Hi all,

I've recently bought a TVR Tuscan Challenge car and it is fitted with air-jacks (4 of them). I've so far been unable to identify them but they look like AP ones. In case anyone can help, they're quite fat (around 4 inches diameter at a guess) with silver body and anodised red tops and locking nuts.

The connections that were in them (no pipes connecting them up) were 20bar push fit pipe connections. After going to my local Pirtek, the guy identified the connections and gave me some nylon pipe suited to the fittings so they're now all plumbed in. Before I start ordering any lance/bottle system to power them off though, does anyone know what sort of operating pressure I'm likely to need? The car is pretty light at around 900kg wet so I wouldn't have thought it would need tremendous pressure, but I have literally no idea at the moment other than < 20bar!

Any thoughts??

[450Nick]

Thanks for the info guys! So it sounds like around 20 bar is about right... I'll see if I can identify the jacks and get a rebuild kit for them... If not I'll jus test them to start with and see how long they sit on them for before dropping...

[450Nick]

Blimey, sounds like I'd better get them serviced or at least tested before proper use then! Managed to get hold of the previous owner and he reckons they used to use an 8 bar compressor and that was plenty... Not sure how that calculation works but apparently thats all they need!

[450Nick]

No, not got any jack stands, though I do intend to get some for the reasons stated above, and so that I can safely stick my arms/head under the car when its up on them to do any quick tweeks under the car. Think I'll have to get some made down the local machine shop. Best get CADing!

[450Nick]

Now here's the odd part, after speaking again with the previous owner (ran two of them in a team), the jacks are actually scratch built by the team. No wonder I couldn't find them on the net! Apparently they took some jacks they had, took them apart to see how they worked, and then built 8 of them specifically for the cars. I would never have guessed this as they have a very high quality of finish, are very well engineered and look to be in 'as new' off the shelf condition. And I would never have guessed that they weren't made by AP or another proper supplier. Anyway, the result of this is that there are no rebuild kits as they're unique.

He has kindly said though that he can send me pictures of the build and make me some more if any are faulty. Regarding operating pressure, he said 'whatever works, though we used to run them off an 8.5 bar compressor with no issues'.

I take it that its not very common to have diy airjacks??

[450Nick]

I assume they are... I can't remember what Danny's ones look like though. I've got pics of his at home and I'll have a good look at mine now I know I'm not going to find any specs for them anywhere. Then I'll get in touch with Craig and see what pressure they run at if they're the same.

I'm amazed at how un-diy they look though. They have very nicely machined threaded bodies, red anodised aluminium bottoms, tops and locking nut things. Rubber 'feet' at the bottom of the jack cylinders and on the whole they feel very well put together. Very impressed. Maybe I'll get him to make me some more and start selling them over here (he's based in Sweden)

Edited by 450Nick on Thursday 19th November 15:43

[450Nick]

Graham said:

We managed to answer the question at the weekend...plugged the workshop air line in and up she came, no problem... the regulator on the compressor was set to around 90 psi.


I hate to say it but a car coming up on air jacks is cool

Oh I agree, it looked (and sounded) very cool when it jumped off the floor... I was really surprised how far up it went as well. I was expecting an inch or two - just enough to get the wheels off, but it went a good 8 inches or so! How high do non 'diy' ones usually go?

90 psi is only 6 and a bit bar as well isn't it? so 10 bar should see it shoot up