| From | Message |
Justin
Dodge Dakota
JOIN HERE
12/18/2005
20:16:21
|
 Subject: low brake pressure
IP: Logged
Message:
I have an 89 Dakota with 215K miles. Recently the brake pedal became very soft and the truck is difficult to stop. Furthermore, as you depress the brake pedal, the anti-lock light AND the brake light both come on at the same time. There system is not losing any fluid. I'm thinking about taking it to the shop and letting them have a look but I'm afraid it will turn into a change every part till they stumble onto the problem type solution. Any suggestions? Feel free to email me here or at JSerpico@datacomcg.com. Thanks.
|
imgreen
GenIII
12/21/2005
23:30:49
|  RE: low brake pressure
IP: Logged
Message:
Sounds like your master cylinder has gone bad. Your anti lock is on to let you know something is wrong. I don't know how mechanically inclined you are but I have replaced 2 master cylinders with anti lock. You can get a reconditioned master cylinder fairly inexpensively. The tricky part is removing the ABS module.
If you choose to replace the master cylinder your self, invest in a manual vacuum pump and about four bottles of brake fluid. As a rule you should replace brake fluid every 2 - 3 years. Moisture will get entrapped in the brake fluid and cause vapor lock as the breaks heat up. You will also see corosion on the ABS module at the fluid ports.
Now the OEM repair manual will tell you to let the dealer repair ABS breaks , mainly due to liability. I personnally am a very subborn person, and have successfully repaired my ABS breaks without any problem. Get a good repair manual and read up.
If it ain't broke, your not trying!
|
Justin
Dodge Dakota
JOIN HERE
12/22/2005
09:00:44
| RE: low brake pressure
IP: Logged
Message:
I know what you mean. I took mine to pepboys for them to bleed, and they said they would have to replace the master cylinder, then the wheel cylinders because they couldn't get the bleed bolt off. $450 is what they said it would cost. I opted to do it myself, and the bleed bolt unscrewed like normal. This is the reason I feel like I can't take my truck in anywhere. I still don't think I needed to replace the master cylinder because it didn't really change anything.
|
imgreen
GenIII
12/22/2005
11:21:42
| RE: low brake pressure
IP: Logged
Message:
When you say "it didn't really change anything" do you mean the brake are still soft and the caution lights are On?
A couple of things to check;
*You may still have air in the brake lines, be sure to bleed all lines until you see no air bubbles and clean fluid. The manual vacuum pump works well but at times the threads of the bleed screw will leak air by, I put nickle base antisieze on the bleed screw threads, this stopped the air from leaking past the threads while bleeding the lines.
*Your ABS module is bad or was not reset properly and is bypassing. Ussually in the box of the new master cyclinder it will tell you how to remove and replace the ABS, also has new o-rings. The ABS module consists of 2 stepper motors and a ported vavle body, when the wheel sensors read a stationairy rotor when the vehical is in motion the stepper motor for that break line engadges, causing brake fluid to bypass back to the resevore cup. There are very specific directions on installation and reseting of the ABS module. Read up on ABS and go over your steps.
*Your New / Remanufactured master cylinder might be defective. It is possible but not very probable.
* Vacuum Leak. The power assist has a vacuum line running to it. If you have a serious vacuum leak it can also cuase poor breaking .
That is all that comes to mind, but there are several good instructional sites that may assist you with the repair.
Good luck,
Mike
If it ain't broke, your not trying!
|
JustinSerpico
Dodge Dakota
JOIN HERE
12/23/2005
18:06:47
| replaced master cylinder
IP: Logged
Message:
hey...first things first...I think we have two Justins posting out here. I posted the first message but a second Justin posted the one about Pep boys. ;) In either case...all the advice has been great so keep it coming...THANK YOU!!!!
Here's the update: I let Chrysler replace the master cylinder. BIG MISTAKE. I should've done it myself but let the cold weather dictate my decision. Hence I was outside all day looking over the system that they can't fix. I bled the system after I got it back and have my pedal pressure where I like it. They also replaced the wheel speed sensor (on the Diff) and yet the anti-lock brake light and brake light still remain on. They were at a loss. For 15 dollars I went and got the Haynes manual for these trucks. After following the manual's directions to short the diagnostic plug I get an error code 4. The book says this is a "closed RWAL valve switch." I have searched the internet high and low and read everything from "there is air or debris in the valve and getting the lights to go off is hopeless" to "flush the entire system with alchohol and you'll be good to go."
First of all: what is the RWAL valve switch and where is it located?
Second of all: is it a serviceable part or should I just get used to no ABS and two idiot lights on the dashboard of this VERY old truck? lol.
Merry Christmas to all...and thanks so much for all the help.
|
| | P 1 |
|
Post a reply to this message:
Username Registration: Optional
All visitors are allowed to post messages
|
