Ok, before i go hijacking chuckwagon976 post about brake booster/servo o-ring any further, i figured id create a new post.
Looking to flush out the brake fluid after a couple years of use and suddenly a notice in less stopping distance while backing up down hill (this happens often in Seattle) and the disappearance of a noticable sqeak on the rear brakes.
Brake fluid in reservoir is a bit dark but still full. I have since removed some of the older fluid from the reservoir and poured in new fluid, never going below the min level. I have used a couple methods to try and get some fluid to come out.
1st go - using hand pump vacuum like this one https://www.harborfreight.com/brake-bleeder-and-vacuum-pump-kit-63391.html
Attach the host to the bleeder (this does not seem snug), open to bleeder and start hand pumping to draw fluid out. I was only ever able to get a dribble of fluid. Closed it back up and tried the rear LH brake, same, but less than a dribble.
2nd go - 2 person method
With the vacuum attached to the rear RH bleeder as well as a bit of pressure on the hose to create a better seal, buddy pumped the brakes and then held down while i opened the bleeder screw and started pumping. I got a bit more fluid out this time, but buddy reported the pedal never released any pressure once the screw was open. Closed it back up and buddy released foot. Did this a couple more times with no success.
3rd go - using a regular brake bleeding kit with a bottle and hose inside the bottle.
Put some brake fluid in bottle to submerge hose, attached to bleeder via the little nipple attachement vs fitting hose over the bleeder, opened and then went to pump. Nothing. Did this on both sides.
4th go - used vacuum directly on brake line
Also tried the vacuum on the brake line itself in teh rear with no results.
So now im looking at what else can be gumming this up. After searching a bit, it looks like this can be caused by a proportioning valve being stuck in a forward position instead of middle. The previous owner gave me a box with some parts, 2 of them being a servo and a pressure reducing valve.
Is the pressure reducing valve the same thing as a proportioning valve? If so, can i just replace and bleed or can i salvage the current one with some work. I am doing this on the street so i dont have readily available access to compressed air (a forum mentioned shooting a quick shot of air in the brake line to try and make it move).
Is there something else I need to be looking at?
Thank you for any insight to help this along.
Rob
Looking to flush out the brake fluid after a couple years of use and suddenly a notice in less stopping distance while backing up down hill (this happens often in Seattle) and the disappearance of a noticable sqeak on the rear brakes.
Brake fluid in reservoir is a bit dark but still full. I have since removed some of the older fluid from the reservoir and poured in new fluid, never going below the min level. I have used a couple methods to try and get some fluid to come out.
1st go - using hand pump vacuum like this one https://www.harborfreight.com/brake-bleeder-and-vacuum-pump-kit-63391.html
Attach the host to the bleeder (this does not seem snug), open to bleeder and start hand pumping to draw fluid out. I was only ever able to get a dribble of fluid. Closed it back up and tried the rear LH brake, same, but less than a dribble.
2nd go - 2 person method
With the vacuum attached to the rear RH bleeder as well as a bit of pressure on the hose to create a better seal, buddy pumped the brakes and then held down while i opened the bleeder screw and started pumping. I got a bit more fluid out this time, but buddy reported the pedal never released any pressure once the screw was open. Closed it back up and buddy released foot. Did this a couple more times with no success.
3rd go - using a regular brake bleeding kit with a bottle and hose inside the bottle.
Put some brake fluid in bottle to submerge hose, attached to bleeder via the little nipple attachement vs fitting hose over the bleeder, opened and then went to pump. Nothing. Did this on both sides.
4th go - used vacuum directly on brake line
Also tried the vacuum on the brake line itself in teh rear with no results.
So now im looking at what else can be gumming this up. After searching a bit, it looks like this can be caused by a proportioning valve being stuck in a forward position instead of middle. The previous owner gave me a box with some parts, 2 of them being a servo and a pressure reducing valve.
Is the pressure reducing valve the same thing as a proportioning valve? If so, can i just replace and bleed or can i salvage the current one with some work. I am doing this on the street so i dont have readily available access to compressed air (a forum mentioned shooting a quick shot of air in the brake line to try and make it move).
Is there something else I need to be looking at?
Thank you for any insight to help this along.
Rob