Jump to content

Due to a hardware failure on the hosts systems, all posts and messages created between May 26th and Jan 13th have been lost. Additionally, if you joined the NPORA Forums community during that time, you'll need to re-register. -NPORA Mod Team *Updated: 05/19/2022 12:15AM PST

Brake bleeding problem


okanagan
 Share

Recommended Posts

My 99 (4wd) has always required a double pump of the brakes since I got it a couple of years ago. Today we used a pressure bleeder and got air out of 3 brakes and the load sensing valve, but cannot get all the air out of the front passenger side caliper. There is just a constant stream of bubbles that never end. We have used 2 quarts and most of this has gone through the last brake. The FSM makes no mention of bleeding/cycling the ABS unit.

 

Any suggestions?

Link to comment
Share on other sites

Some R50s have load sensing valves near the rear axle. I don't remember what year they quit using those, but this guy had a hell of a time getting air out of his brakes until he got the bleeder on his LSV cracked loose. Something to check.

 

I've seen a bunch of bubbles come down a brake bleed line recently when I was bleeding an F150. When I pressed the pedal, fluid came out; when I didn't press the pedal, I got bubbles. The brakes felt fine when I shut the bleeder. I think what was happening was that the fluid trying to go down the hose I had on the bleeder was drawing in air around the bleeder threads. Maybe I had the bleeder threaded out too far, maybe the threads were just cut (or worn) loose. Either way, I don't think the bubbles were coming from inside the caliper.

Link to comment
Share on other sites

Some R50s have load sensing valves near the rear axle. I don't remember what year they quit using those, but this guy had a hell of a time getting air out of his brakes until he got the bleeder on his LSV cracked loose. Something to check.

 

I've seen a bunch of bubbles come down a brake bleed line recently when I was bleeding an F150. When I pressed the pedal, fluid came out; when I didn't press the pedal, I got bubbles. The brakes felt fine when I shut the bleeder. I think what was happening was that the fluid trying to go down the hose I had on the bleeder was drawing in air around the bleeder threads. Maybe I had the bleeder threaded out too far, maybe the threads were just cut (or worn) loose. Either way, I don't think the bubbles were coming from inside the caliper.

 

Like he said: ^

I would be expecting those bubbles to have been coming in around the bleeder or bleeder hose.

There just aren't a lot of places for those bubbles to be hiding between the master and the right front caliper.

 

If the air was coming in anywhere else then you either let the master cylinder empty while bleeding, or you must have such a bad leak there would be no fluid in the front brakes whatsoever.

 

I doubt either of those are the case, so suspect it's just a bad seal at the bleeder hose.

 

How do the brakes perform?

Link to comment
Share on other sites

  • 4 weeks later...

Installed new bleeders on the front brakes and then did another round of bleeding after cycling the ABS on a dirt road. The steady stream of bubbles stops when we hold the bleed jar up a bit. Very strange.

 

The brakes are still the same. Double pump every time for the best braking.

Link to comment
Share on other sites

Makes sense it would bubble less when you hold it up--if it's drawing in bubbles around the bleeder, it's doing it because the fluid going down the tube is creating suction behind it. Reduce the vertical distance from bleeder to bottle and you reduce the suction.

 

If you've bled everything (including the ABS block or LSV or whatever else is under there), I'd be suspicious of the master cylinder.

Link to comment
Share on other sites

For what it's worth, you're not the only one experiencing the double pump issue, my 01 has been this way for as long as I can remember. The brakes aren't bad on the first hit, but the pedal is definitely higher and more firm with a second pump. Been through the entire system, even enlisted the help of a good friend who owns a repair shop, everything has checked out fine, bled everything, then power bled, no change. I've owed it since new, unfortunately I don't remember how they felt back then, but it's been this way for years.

Link to comment
Share on other sites

I should mention.. I did not have the issue spoken about here until I changed my brake shoes in the rear. I believe my double pumping for a more stiff brake pedal is because the rear shoes are not adjusted well at all and the wheel cylinders are fully extending during the fist brake pump and after braking the springs push it all back together, then the cycle repeats.

 

I’ve pulled the ebrake hundreds of times to get the shoes to auto adjust but that function isn’t working for whatever reason. I need to get under there and make the adjustment by hand since there is a hole next to the bleeder where a flat head screw driver or brake tool can be used to make the adjustment.

 

 

Sent from my iPhone using Tapatalk

  • Like 1
Link to comment
Share on other sites

Food for thought at least. I do remember the last time I did rear brakes on mine, I adjusted them, with a brake spoon, through the hole, just as I have always done with every set of drum brakes I've ever done. The result was a nice firm pedal, good, even braking, but the first time I went to apply the hand brake, it wouldn't come up more than a click or 2, backed the adjustment down slightly and ended up with the softer, slightly less responsive pedal.

Link to comment
Share on other sites

  • 2 weeks later...

Back brakes are more responsible for your brake feel than the front ones. Adjusting them correctly will stiffen up the feel a lot. other than that, if the lines are old and getting wore out, when u first hit the break the lines expand slightly and that will cause that squish feeling, pumping it makes it feel more firm because the lines are finished expanding so there is no "give" so to speak on the second pump. ;P

 

Hope this helps

P

Pat head mother effer ;

  • Like 1
Link to comment
Share on other sites

Back brakes are more responsible for your brake feel than the front ones. Adjusting them correctly will stiffen up the feel a lot. other than that, if the lines are old and getting wore out, when u first hit the break the lines expand slightly and that will cause that squish feeling, pumping it makes it feel more firm because the lines are finished expanding so there is no "give" so to speak on the second pump. ;P

 

Hope this helps

P

Pat head mother effer ;

 

One of the things on my list of 'things to do' is replace the brake lines. Mine have felt the same way as described for the last 70,000 miles, or as long as I have owned it. I've bled, and rebled, had it bled at the shop, adjusted the rear brakes, etc. and my thoughts are that it is likely the lines need changing to firm up the pedal.

Link to comment
Share on other sites

  • 3 months later...
  • 2 weeks later...

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

Welcome to NPORA Forums

 

Please register to gain full access to the forum.

Make sure you read the Forum Guidelines and don't forget to post a new intro in the New People Start Here! section, to say hi too everyone.

 

-NPORA

×
×
  • Create New...