brakes Soft Break Pedal

[Fox2115]

Hey all,

I recently replaced the master cylinder in my 1973 2002. At the same time I replaced the calipers in the front as well as the pistons in the rear drum breaks. After I installed everything I bled the brakes about 6 separate times. However I am left with a break pedal that feels like it has way too much travel. It doesn't necessarily feel squishy, like there is air in the lines. Rather, my foot has to travel almost to the floor before the pedal feels firm. I have tried adjusting the rear drums as well with little change in the firmness of the the break pedal. Any ideas of what could cause the break pedal to travel so far? Thanks for your input!

[M3M3]

Bleed with a pressure bleeder and try a search using "soft brake pedal" as the search term. Lots of useful info available.

[Stevenc22]

I feel your pain. Did mine 6 months ago and had the exact problem. Never really found a response that answered my problem. Over time the pedal is has gotten better but realistically its not perfect. No way i could lock up the brakes if i had to. I tried 2 different master cylinders. Pressure bleeding and regular bleeding and never fixed the problem. Almost as if the brakes have the potential to work good but we run out of pedal travel before they really grab.

[eurotrash]

slowly pump the brake pedal while the pressure bleeder is doing its thing..  several times.  You probably have air in the master.

['76mintgrün'02]

Is it true that you should not push the pedal clear to the floor while doing this?

It seems like I have read that this can do damage...

 

Also, you probably already know this, but there is a proper sequence to bleeding.

I had to refresh my  memory, so I pulled this up.

 

Start with the right rear, then the left rear, then the right front, and then the left front, with the clutch slave cylinder last.

The correct bleeding sequence for the calipers on a 2002 are top nipple, inner nipple, outer nipple.

[jireland2002]

Apply the parking brake and see if it makes a difference.  If it makes a big difference the problem is at the rear.

Excessive peddle travel can also be in the linkage. 

You might try >> Jack up the front and have a friend spin a wheel as you very slowly apply the brake and see when the brake grabs.

[TobyB]

 

Is it true that you should not push the pedal clear to the floor while doing this?

It seems like I have read that this can do damage...

Yes, but only with an old master that's never gone to the floor.  At which point, well, don't you

want to replace it anyway?

 

I third (4th?) the rebleed recommendation, but also add- stomp the pedal a bit.  Like, sitting in the driveway,

imagine an Audi pulling right out in front of you and you're panic- stopping.  Try this 10 times.

See if it helps.

 

I've had caliper seals that are over- retracting the pistons until they get really worked- then they work fine after

that.  I'd also add heat- but that was a race car on a closed course.  Dang, it was a scary few laps double- pumping the

pedal, but after that and a re- bleed, they were fine. 

 

Also, take a 16oz hammer and rap on the inner and outer calipers a few times.  That helps dislodge air bubbles,

and they'll bleed out after that.

 

hth

 

t

[Hans]

Perhaps revisit the rear brake adjustment. How worn are the drums? 

[M3M3]

 

 

Also, you probably already know this, but there is a proper sequence to bleeding.

I had to refresh my  memory, so I pulled this up.

 

Start with the right rear, then the left rear, then the right front, and then the left front, with the clutch slave cylinder last.

 

that is an old wive's tale from the early days of cars.  on a 2002  it makes no difference at all which corner of the car you do first or last.  the rears are the same distance from the master and the fronts all have their own lines off the master.

 

the clutch has its own line off the reservoir, so it does not matter if you bleed that first, last or in the middle of the brake process.

['76mintgrün'02]

that is an old wive's tale from the early days of cars

 

I was searching for the bleeder sequence for the calipers and the other info was there, so I put that too.  

 

I remembered you mentioning this the other day, but you had not explained the reason.  

 

Furthest to closest is an old wives tale. It makes no difference which one you do first or last.

 

Searching using "wive's tale"  did not get any hits, but "wives tale" brought this one up as well

 

does not matter which wheel you do first. they are all on different lines. the rear brakes are on the same line, but they are exactly the same distance from the MC as the fluid goes. old wives tale that you have to do the right rear first.

 

Thank you for explaining why the farthest to nearest is not necessary on these cars.  

It makes sense now.

[M3M3]

Early cars had single circuit brake systems. One line off the master that was then split to go to all the calipers. Chasing the air out of the longest part of that run first made sense. Modern brakes with individual brake circuits for each wheel do not have this issue. 2002's have a three circuit system. One rear, two front. The rear line splits in the middle, so distance is equal. Front has two parallel circuits, but there are individual lines for each of the four off the master, so you don't have to case air down any branches.

[Napes]

Marshall's explaination makes perfect sense, BUT, I have to start somewhere so I may as well start in the right rear, proceed to the left rear, then the right front and lastly, the left front.  May not be important, but this is the way I do it.

 

Bob Napier

[jgerock]

Please clarify on the rear brakes:  Did you replace the entire wheel cylinder assembly or did you "rebuild" the existing wheel cylinder using new pistons and seals?   It is very uncommon to rebuild old wheel cylinders - easier to replace the entire unit.

[M3M3]

Marshall's explaination makes perfect sense, BUT, I have to start somewhere so I may as well start in the right rear, proceed to the left rear, then the right front and lastly, the left front. May not be important, but this is the way I do it.

Bob Napier

Right on Bob. While there is no science to that order anymore, having a repeatable process so that people like, well, ME, don't forget which corners they have done already is a good plan.

Edited October 16, 2014 by mlytle

[Fox2115]

I replaced the whole rear cylinders in the rear breaks rather than just rebuilding them.  Thank you all for the help with this.  I get my car back from getting painted next week and will give these methods a shot.  I'll be sure to follow back up with any progress.