Flushing Brake Fluid

[jcas]

Hi Chaps,

Is there any recommended way of flushing out old brake fluid? I have a car that has been standing for over a year, and the brakes weren't that good when it was laid up. First thing I want to do is get some new fluid in there but can it become contaminated with the old stuff?

Cheers,
James

[dern]

I've never done anything other than bleed out the old fluid through one caliper until the reservoir was nearly empty and then fill up and repeat a few times. Then do half the reservoir through the other front and the a reservoir worth through each of the backs. This seems to work fine even with very old fluid.

Mark

[phumy]

Normally, start bleeding fluid at the furthest caliper from the reservior, then work you way closer, caliper by caliper, not forgetting to keep an eye on the fluid level in the reservior.

Or get an easi-bleed and follow the instructions, bery easy to use and ideal for changing system of old fluid.

[jcas]

So no problems if the old and new fluids mix then?

[dilbert]

The only place they could mix (other than the tank) is in the pipe. If you flush a litre of fluid through, the mixed bit is only going to be 6 inches worth of pipe, or a master cylinders worth (worst case), which is a tiny quantity by comparison.

If you are flushing though, the normal recommendation is to empty (and refill) the tank first.

I think you can get, although I have never used, brake fluid which is coloured specifically so that you can see when it is flushed completely through.

Edited by dilbert on Wednesday 14th May 16:01

[HRG]

Get a Gunsons eezibleed and a proper nipple spanner. You'll soon see the fluid change colour when the new stuff is through Start at the caliper furthest from the reservoir and work your way back. Only takes a few minutes with the right tools.

[jonamacg83]

When flushing it should be very obvious when the new fluid comes through. The old stuff is likely to be a darker murkier colour

Jonny

[Skyedriver]

Please excuse my ignorance but, with a normal steering rack there is oil in it to lubricate the moving parts. On a power steering rack, does the PAS fluid do that lubrication or should there still be oil in the gaiters etc
Sorry but the last rack I pulled apart was a Hillman Imp one about 30 year ago.

[HRG]

If your gaiters are full of a reddish colour oil on a PAS rack chances are the PAS fluid is leaking past the seals. Some lube is fine, but they aren't usually swimming in it.

[tr7v8]

Going back to the brakes, I always syringe out most of the fluid from the m/c so the dirt & muck in loads of fluid don't have to go through the m/c seals. You want a bladder syringe, according to my wife who is a nurse, that's what she supplies me with!