1998 safari AWD master cylinder?

[rbh]

Changed the front pads on the wifes vehicle a few weeks back and noticed the back drums on the one side where a bit rusted inside and the other side not worn alot, we checked the backs by applying a brake application and the backs did engage.

Since then the vehicle still seems to use to much of the front brakes and not alot of the back (fronts are very hot)
ABS light now on constantly.
Could the master cylinder be old and bypassing fluid during a brake application allowing only a little fluid pressure to go to the back brakes?

Thanks
Rob

 

[bruceb58]

Re: 1998 safari AWD master cylinder?

You need to find someone who has a scanner to see what's wrong with the ABS. A regular OBD2 scanner won't be able to do it.

 

[MTboatguy]

Re: 1998 safari AWD master cylinder?

Do you guys have Autozones in Canada, if so, they will have a scanner to plug in and check your system, they don't charge for this service.

 

[Idlespeedonly]

Re: 1998 safari AWD master cylinder?

I bet the master cylinder is bad. Is this 4 wheel abs? And does it have hydro-boost?

 

[rbh]

Re: 1998 safari AWD master cylinder?

I bet the master cylinder is bad. Is this 4 wheel abs? And does it have hydro-boost?

Not sure, but the ABS light is off till you do a brake application.
It resets itself???

 

[bruceb58]

Re: 1998 safari AWD master cylinder?

Not sure, but the ABS light is off till you do a brake application.
It resets itself???

That's quite a bit different than on constantly. May or may not have a code for that.

 

[rbh]

Re: 1998 safari AWD master cylinder?

That's quite a bit different than on constantly. May or may not have a code for that.

Let me rephrase that, the ABS light is off till you do a brake application then it stays on till you turn the key off.

 

[bruceb58]

Re: 1998 safari AWD master cylinder?

Let me rephrase that, the ABS light is off till you do a brake application then it stays on till you turn the key off.

This is where a factory service manual comes in handy!

Autozone will likely not have the code reader to help you here. These will be manufacturer specific codes.

 

[Idlespeedonly]

Re: 1998 safari AWD master cylinder?

I have an Innova 3130 it has read every abs code for me so far. Is it the actual abs light or the brake light?

 

[rbh]

Re: 1998 safari AWD master cylinder?

I have an Innova 3130 it has read every abs code for me so far. Is it the actual abs light or the brake light?

ABS light in the dash cluster

 

[MTboatguy]

Re: 1998 safari AWD master cylinder?

Bruce, Autozone has the same readers that the manufactures do, I looked at it last time I needed to have a code read on my Ford and it said right on it, for use by Ford Authorized Facilities, which Autozone is.

 

[bruceb58]

Re: 1998 safari AWD master cylinder?

I have an Innova 3130 it has read every abs code for me so far. Is it the actual abs light or the brake light?

Depends if its in this set of generic codes or chassis codes.

Generic OBD-II C Chassis Trouble Codes

 

[bruceb58]

Re: 1998 safari AWD master cylinder?

Bruce, Autozone has the same readers that the manufactures do, I looked at it last time I needed to have a code read on my Ford and it said right on it, for use by Ford Authorized Facilities, which Autozone is.

Good to know.

 

[MTboatguy]

Re: 1998 safari AWD master cylinder?

Good to know.

One of the benefits of living in a small town, is you get to know people, normally when I go to the store, the manager tells me, look it up, go get it and pay for it on your way out, compared to other AZ I have been in, in other towns ours is quite small.

 

[bruceb58]

Re: 1998 safari AWD master cylinder?

One of the benefits of living in a small town, is you get to know people, normally when I go to the store, the manager tells me, look it up, go get it and pay for it on your way out, compared to other AZ I have been in, in other towns ours is quite small.

I saw the code reader they use at my local autozone and it was a cheap $100 unit. That is why I have my own. My understanding is that not all even read codes anymore.

This is the one I have and I have the enhanced Toyota interface package as well.
http://www.autoenginuity.com/products/scan-tool.html

 

[dolluper]

Re: 1998 safari AWD master cylinder?

When was the last time you bled the system....old water soaked fulid?...A good bleed with fresh brake fulid can do wonders on ABS systems and save the ABS controller.....big bones to replace

 

[CharlieB]

Re: 1998 safari AWD master cylinder?

I'm not sure I understand correctly.

The inside surface of the brake drums are rusted, yet when you applied the brake they held?

I'm wondering if you applied the PARKING brake and the brakes held.

The rear brakes are self-adjusting. When the vehicle is backing up and the brakes are applied with sufficient force the mechanism will ratchet the adjuster, tightening the brakes.

It is very common for many drivers NOT to hit the brakes hard enough for the mech to operate. Which eventually leads to in-effective rear brakes during normal braking, YET the parking brake may still function.

Jack the rear of the vehicle and set on sturdy jack stands.

Run in Reverse so the wheels turn and hit the brake pedal HARD. Listen carefully, you may hear the mech 'click' as it tightens. Repeat stabbing the brake HARD until no more 'clicks'.

Or you can grab a screwdriver or brake tool and adjust them up.


The brake light may be coming on because the excess fluid movement to the rear causing the balance switch to trigger.

Once the brakes are adjusted correctly it should stay off.

 

[rbh]

Re: 1998 safari AWD master cylinder?

^^^
The rear brake shoes are fully adjusted on both sides, one side shows engagement but the other side showed minor rust as if it was not engaging.
When we attempted to see if the rear brakes where engaging we did a brake application and attempted to rotate by 'hand' the brake drum and they both would not move.
What I think is happening is there is either air in the brake lines to the rear brakes or the master cylinder is only applying marginal pressure to the rear brakes and the fronts are doing most of the work.

 

[NYBo]

Re: 1998 safari AWD master cylinder?

Disk brakes require more pressure but less volume than drums. The front brakes, due to weight shift, do most of the work, something on the order of 75-80%. Your first problem is with the rear brake that isn't engaging. The ABS problem is probably a wheel sensor but as noted already, you'll need to have the system scanned for error codes.