My K100, 1990, with ABS, is due for a brake fluid flush. I have
gotten hold of a vacuum pump that airconditioner people use. I connected
the suction spiggot of the pump to the lid of a glass jar using a 6mm plastic tube, and with
another connection from the same lid, to go to the bleed nipples of the
ABS modulator and calipers. I've tried it on the bench and
it can fill the jar very quickly from a bottle of old brake fluid...too
much suction. I will install a valve in series with the vacuum line to
try and control the suction.

My reading so far (the recent "How to..." articles that Bert posted, great stuff!!) indicates that the
modulator/master cylinder line should be flushed first, then the RHS
front caliper and the the LHS front caliper for the front brakes. For
the rear brakes, master cylinder/modulator line and the the rear
caliper.

My understanding is that as long as the master cylinder
has fluid in it for the whole duration of the flushing (sucking) process, that no
grief will be encountered.

Are there any special traps I need to look out for, as I have not done this before?

Thanks,

Rick G.

(PS, off to Phillip Island for the SBKs and Alpine Way and Victorian Alps on Wednesday, for six day ride! Will do the flushing upon my return.)

What comes to mind is having a bucket of water and a cloth handy in case you spill some on the paintwork.

<<<<is jelous rick .......sounds like bliss to me .......enjoy friend

As you mentioned it that is the same way I did my 89 K100LT ABS
and I had no problems just made sure I did not run the master cylinder low on fluid and did the job slowly and as Blakey said cover your paint work and mop up any spillage quick.

BIG D

Thanx, Lads! I've been laying in bed at night...if I can get hold of an old fluid reservoir lid, screw in a spiggot, get another jar with a spiggot in the lid and a copper tube from the inside of the spiggot down towards the bottom of the jar, connect the two with tube, fill the jar with new brake fluid. As the fluid is sucked from the modulator/caliper, the fluid level in the master reservoir will fall, causing clean fluid to be sucked into the reservoir, a more or less closed system. A bit "Gyro Gearloosey" but I might make further bench tests.

Has anybody out there done/seen this sort of thing before?

This is what I use when the going gets tough, ie, I'm not using the milking-a-cow manual method. It attaches to an air compressor, then the nipple of the caliper you're bleeding, by pulling the nasty old fluid down into the receptacle, and is quite efficient. You have to keep a close eye on the master cylinder's fluid level, however. I think it cost me around thirty AUS dollars a coupla years ago from the local Trade Tools Direct. The brake lever's left firmer than a catwalk model's tummy.

Harbor Freight sells an inexpensive bleeding pump as well. No compressor though, just squeeze the handle to create the vacuum.

I have the Harbor Freight hand pump tool as well. It does a good job as Wayne states, but does pull that liquid down quickly. Have clean fluid ready to go into the reservoir before squeezing!

Two Wheels Better wrote: The brake lever's left firmer than a catwalk model's tummy.

hmm i better go back school ...i never did that corse ....with the models tummy before ....grin


lots of great info guys .....Thanks all

I do mine from the bleed nipples UP...Crazy Frog has the best syringe to do the job. Lots on this in previous postings.
Ajays

For those of you that like to bleed your brakes the "other" way (squeezing the lever and twisting the bleed screw), zip-tie a piece of wood to the right hand grip so that it stops the brake lever traveling too far.

This limits the travel of the piston into the area that it normally doesn't travel, so you won't tear-up your seal if you have a corroded bore.

Smart cookie!