Brakes soft

Tiny
BILL29211
  • 2002 DODGE CARAVAN

Brakes problem
2002 Dodge Caravan 6 cyl Front Wheel Drive Automatic 108000 miles

I replaced the rear cylinders and bled all the lines (several times) but the brakes are still soft and at times while pressure applied just fall to the floor after being somewhat stiff. Can this be the master cylinder and are there any tricks to changing one when you have abs?

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Monday, August 17th, 2009 AT 6:03 AM

31 Replies

Tiny
BMRFIXIT
  • EXPERT
  • 19,478 POSTS

Pump brakes does the peddle go up and if so most likely you have air in the system and have to bleed again
changing master cylinder will not help
if need to change master cylinder

Have to bench bleed new master cylinder until all air out before installing it in

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Monday, August 17th, 2009 AT 6:21 AM
Tiny
BILL29211
  • MEMBER

Is there a specific pattern for bleeding? Should the van be running or not? Is there any bleeding that should be done where the lines go into the abs box?

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Monday, August 17th, 2009 AT 7:15 AM
Tiny
BILL29211
  • MEMBER

Should we pump them and then hold them to the floor and then open each one? And repeat. Repeat. Repeat. Until all 4 are done?

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Monday, August 17th, 2009 AT 7:18 AM
Tiny
JACK42
  • MEMBER

Engine off, start farthest away from the master cylinder and work your way towards it. Does the pedal fall if you apply light pressure, but if you hit it hard it is ok?If so the master may be by-pasing internally, which would require another one. As said before you need to bench bleed it to get the air out before installing it. I prefer to open the bleeder, then slowly push down, close bleeder and let up slowly

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Monday, August 17th, 2009 AT 3:07 PM
Tiny
BILL29211
  • MEMBER

After bleeding you will get some o.K. Pressure. Without letting up, the pedal will sometimes fall all the way to the floor. Sometimes if you just lighten up and then press again it will then fall to the floor.
I ordered a master cylinder today and will have it tommorrow. Can you give me the low down on this replacement. The vehicle has abs.

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Monday, August 17th, 2009 AT 3:25 PM
Tiny
BMRFIXIT
  • EXPERT
  • 19,478 POSTS

THIS SHOULD COVER IT ALL

When performing bleeding procedure, ensure rear brakes shoes are properly adjusted.
Ensure master cylinder fluid level remains close to FULL mark.
Check master cylinder fluid level periodically while bleeding brake system.
Add DOT 3 brake fluid as required.

Manual Bleeding
Fill master cylinder (if necessary).
Reinstall master cylinder cap.
Install clear hose on left rear bleed screw.
Place other end of hose in clean transparent container of brake fluid.
Ensure end of clear hose is submerged in brake fluid.
Pump brake pedal 3-4 times.
Hold brake pedal down.
Open bleed screw at least one full turn.
Brake pedal will drop to the floor. Close bleed screw. Release brake pedal.
Repeat bleeding procedure until brake fluid flow is clear and free of bubbles.
Bleed remaining brakelines in proper sequence at each wheel.
Ensure bleed screws are tightened to specification.
BRAKELINE BLEEDING SEQUENCE
All Models LR, RF, RR, LF

BENCH BLEEDING MASTER CYLINDER
NOTE:Bleeder tubes must be installed on master cylinder when performing bleeding procedure.

Clamp master cylinder in soft-jaw vise at mounting flange on master cylinder.
Install Bleeder Tube (6920) in each outlet port on master cylinder with ends of bleeder tubes positioned in brake fluid reservoir on master cylinder. Fill master cylinder with brake fluid.
Ensure ends of bleeder tubes are submerged in brake fluid in in master cylinder reservoir.
Using wooden dowel, slowly depress pistons in master cylinder and then release, allowing pistons to return.
Repeat procedure until no bubbles exit from bleeder tubes.
Remove bleeder tubes and plug master cylinder outlets to keep fluid from draining

MASTER CYLINDER
Removal

CAUTION:Master cylinder is used to create a seal for holding vacuum in power brake booster. Vacuum in power brake booster must be released before removing master cylinder. Ensure area around master cylinder filler tube, master cylinder fluid reservoir and master cylinder-to-power brake booster are clean before servicing master cylinder. Area may be cleaned with brake parts cleaner.

Release vacuum from power brake booster by pumping brake pedal several times with engine off until brake pedal becomes firm.
Clean area around master cylinder filler tube and master cylinder fluid reservoir.
Remove master cylinder filler tube from master cylinder fluid reservoir by pushing filler tube downward and rotating filler tube.
Remove filler cap from master cylinder filler tube and install on master cylinder.
Disconnect electrical connector at brake fluid level sensor located on master cylinder fluid reservoir. Place shop towel under master cylinder to absorb brake fluid.
Disconnect brakelines from master cylinder.
Install plugs at brakeline outlets on master cylinder. Clean master cylinder-to-power brake booster area to prevent dirt particles from falling into power brake booster.
Remove master cylinder-to-power brake booster nuts, and slide master cylinder from power brake booster.
Remove master cylinder-to-power brake booster vacuum seal from groove on mounting flange of master cylinder by pulling vacuum seal from master cylinder.
DO NOT pry vacuum seal from master cylinder.
Installation
CAUTION:Master cylinder-to-power brake booster vacuum seal must always be replaced. DO NOT reuse vacuum seal.

Bench bleed master cylinder before installing. See above
Ensure NEW master cylinder-to-power brake booster vacuum seal is squarely installed in groove on mounting flange of master cylinder before installing master cylinder.
Ensure push rod in power brake booster aligns with piston in master cylinder.
Tighten master cylinder-to-power brake booster nuts and brakeline nuts to specification.

On models without ABS, bleed brake system. See BLEEDING BRAKE SYSTEM ABOVE .
On models with ABS, it is not necessary to bleed Hydraulic Control Unit (HCU), but base brake system must be bled. SEE BLEEDING BRAKE SYSTEM ABOVE

GOOD LUCK

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Monday, August 17th, 2009 AT 5:26 PM
Tiny
AANDRUS7
  • MEMBER

Had the exact same problem with my 2002 Dodge Grand Caravan. Replaced the master cylinder and bled all 4 wheels on 5 different occasions. Each time the brakes returned to normal but over a period of weeks the pedal gradually became softer with increased travel. Eventually it would go to the floor and have no stopping power. There were several rather mystifying points; first of all very little or no air seemed to be expelled with each bleed. Even when the pedal traveled near or to the floor, there was no red brake warning light and there was no ABS light or fault codes. The culprit was something relatively simple; the lower slide pin in the left front caliper mounting bracket was frozen. It had no in and out movement whatsoever. Normally you would think the end result would be abnormal brake pad wear, but the resulting improper movement of the caliper piston not correctly drawing the outboard brake pad into proper contact with the rotor can and will gradually produce a soft brake pedal. Definitely something worthwhile to check.

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Wednesday, April 26th, 2017 AT 3:51 PM
Tiny
2CARPROS KEN
  • ADMIN
  • 10,896 POSTS

Hey,

Great addition to this thread! Please feel free to help out on the site whenever it can add information that will help.

Cheers, Ken

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Saturday, April 29th, 2017 AT 3:06 PM
Tiny
HYKNWOLF
  • 1992 DODGE CARAVAN

Brakes problem
1992 Dodge Caravan 6 cyl Front Wheel Drive Automatic 141000 miles

Noticed a burnt brake smell, brake light came on (parking brake pedal was not depressed), and mushy brakes while driving. The brake fluid level is good. When looking at the front passenger wheel, I noticed the valve stem cap for the tire was melted onto the stem. I had just filled that tire with air last night, and the valve stem cap was fine. I'm thinking the parking brake may not have fully released from the last time it was depressed. If that is the case, what is involved in repairing?

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Saturday, April 29th, 2017 AT 3:07 PM (Merged)
Tiny
KHLOW2008
  • EXPERT
  • 41,937 POSTS

Hi Hyknwolf,

Thank you for the donation.

The parking brakes are at rear wheels so do not affect the front brakes.

The problem is most probably caused by a sticking caliper piston. You would need to remove the caliper and test if it is stuck and not returning to give the pads sufficient clearance to prevent premature wear and seizing of brake pads.

Other possible causes would be seized slider bolts, bad/clogged flexible hoses or proportioning control valve (ABS pump if equipped).

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Saturday, April 29th, 2017 AT 3:07 PM (Merged)
Tiny
KRLAMB
  • 2005 DODGE CARAVAN
  • 6 CYL
  • FWD
  • AUTOMATIC
  • 80,000 MILES

I replaced the rear brake pads and rotors and the brake pedal is soft.

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Saturday, April 29th, 2017 AT 3:07 PM (Merged)
Tiny
CARADIODOC
  • EXPERT
  • 28,841 POSTS

Soft after the new pads or was the pedal soft before too? Did you pump the pedal to push the pistons out? Did you push the pedal all the way to the floor or stop half way?

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Saturday, April 29th, 2017 AT 3:07 PM (Merged)
Tiny
MHPAUTOS
  • EXPERT
  • 31,507 POSTS

Do a full brake fluid flush with a re bleed, let us know what the results are after that.

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Saturday, April 29th, 2017 AT 3:07 PM (Merged)
Tiny
RWILLEY
  • 2005 DODGE CARAVANDODGE CARAVAN

1997 106,000 MILES
BRAKES WENT SOFT, PEDAL TOO FLOOR.
REPLACED MASTER CYLINDER
2 DAYS LATER BRAKES SOFT, REBLEED.
4 DAYS BRAKES SOFT, REBLEED
TODAY BRAKES SOFT THIS WILL BE 6TH REBLEED
NO FLUID LEAKING ALL CONNECTIONS TIGHT.
HELP

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Saturday, April 29th, 2017 AT 3:07 PM (Merged)
Tiny
SERVICE WRITER
  • EXPERT
  • 9,231 POSTS

Did you replace the M/C with a new one or reman?

I would plug remove the lines & plug the connector holes in the master cylinder. The pedel should be rock hard. If not, get a new M/C.

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Saturday, April 29th, 2017 AT 3:07 PM (Merged)
Tiny
RWILLEY
  • MEMBER

THIS WAS A NEW MASTER CYLINDER

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Saturday, April 29th, 2017 AT 3:07 PM (Merged)
Tiny
SERVICE WRITER
  • EXPERT
  • 9,231 POSTS

If you have abs, I think you may need a scanner to bleed that portion of it.

There may be somthing allowing air to enter the system, but still not leak out.

Couple suggestions that may help, do the wheels in this order:
LR, RF, RR, LF
HAve the bleeders opened a full turn after fluid starts coming out.

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Saturday, April 29th, 2017 AT 3:07 PM (Merged)
Tiny
BC11860
  • 2004 DODGE CARAVAN

Brakes problem
2004 Dodge Caravan 6 cyl Front Wheel Drive Automatic 145, 00 miles

Hi, I put new pads & rotors on the front of my 2004 Grand Caravan ( front disc / rear drum ). Which I've done a few tmes before with no problems. Until now. I started at right front, took the caliper off, pads off and proceeded to push the piston back in with a c-clamp. After I did that successfully, I remembered that I didn't remove the master cylinder cap. Thinking there was no harm done, I finished the r/f brakes, proceeded to do the L/F but, decided to remove the M/C cap before pushing the piston in. Finished the L/F brakes no problem. Went to back out of the garage and the brakes would not "pump up"! OK, that never happened before, so I decided to bleed just the front, figuring the rears weren't affected and actuslly, I'm not quite sure how air would've gotten in the lines anyway. Aggravation sets in and I figured to bring it to a garage to let them look at it. The garage said it was a bad master cylinder. They installed a new cylinder, checked the rear brakes, bled all the brakes and said the pedal was good. Wonderful! I hop in the car start it and the pedal goes right to the floor! Wait, I shouldn't say that exactly because while I do have SOME braking, the pedal is spongy and when I keep my foot on it (say at a light) it will keep the braking but, the pedal will "weep" down to the floor? Bring it back to the garage and they say it has to be a bad M/C. OK, I'll buy that so, I leave it for 2 days and they call and say "we brought the car in the bay and the pedal pumped-up fine but, we noticed a "grabbing" on the R/R wheel, which we found was a blown wheel cylinder, which we replaced, bled the system, drove it around and it's working great. It wasn't a bad M/C afterall" OK, now they got it! Picked it up, after hours and wouldn't you know it. The same FREAKIN' problem is happening as when I first drove it in! I am totally baffled! I am getting braking but, the pedal is drifting rapidly to the floor! Is there any way it could be that the BRAND NEW master cylinder is still bad (entirely possible) or could it somehow be a bad brake booster? I'm at a loss and apparently so is the garage! I apologize that the donation isn't super high ( which I'm sorry for) but this brake problem is rapidly draining our finances. Which are slim to begin with.I sure would appreciate any help you could provide! Thank you.

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Saturday, April 29th, 2017 AT 3:07 PM (Merged)
Tiny
MERLIN2021
  • EXPERT
  • 17,533 POSTS

Bleeding sequence here is LR,RF,RR,LF


http://www.2carpros.com/forum/automotive_pictures/62217_Caravan_Bleed_1.jpg


It sounds like a bad master, or not properly bench bled Of course with 145,000 if these are still original calipers, you may have pushed some sludge into the hieght sensing prop valve, or the abs system, is abs or red brake light on?

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Saturday, April 29th, 2017 AT 3:07 PM (Merged)
Tiny
BC11860
  • MEMBER

Thank you for the reply Merlin, Those are indeed the original calipers. As I mentioned before, I've done brakes many, many times and this is a first for me. I'm not an auto mechaic by any means.I am a turf equipment mechanic at a local golf course, which I work on anyrthing from small lawn mowers, to construction equipment, to our own road vehicles, so I can get around autos decent. Not great but, decent! I'm not sure what to do next, well, yes I do know I need to reapir ASAP but, I can't see bringing it back to the garage as we're not on the same page as to what the pedal should feel like. I'm into them for $300.00 for a situation which hasn't gotten better one bit. Is there anything you've mention, besides the bleeding sequence, which I can handle myself (ie, prop valve) or do I bring it to the dealer and hopefully let them figure it out? I wish I had the money to let the dealer have a go at it, believe me. But I don't. I suppose I could do the old beg, borrow or steal, which we're doing already ( except the stealing part, of course ). Thanks again for your reply and any further help will be greatly apprteciated! Brian

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Saturday, April 29th, 2017 AT 3:07 PM (Merged)

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