90 Cherokee brake problem

[jramos]

Hello everyone, I currently own a 90 Cherokee that is equipped with abs, now as I was driving down the freeway coming up on my exit the red brake light on the dash came on and the pedal got hard and I can feel a slight pulse while applying pressure. Now, the engine will run but when it reaches normal operating temp the brake light comes on and it dies, you can crank it but almost resembles a no fuel problem. Does anyone know if the brake problem could be causing the engine to die and not restart?? Any help on this would be greatly appreciated thanks... my email is jramos964@gmail.com thanks.

 

[SteelHeadz]

Red brake light indicates low fluid level. Hard pedal indicates the lack of brake assist ( brake booster failure) meaning, an internal or external vacuum leak. A sudden large vacuum leak can cause the engine to stall. Are any of these issues evident?

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[jramos]

No visible or audible vacuum leaks, is an abs system equipped with a booster???

 

[mud4feet]

If you have power brakes (which you do), then you have a booster......regardless of the ABS. Already replaced mine on my Cherokee.

 

[jramos]

I'll double check but dont recall seeing a booster in the usual firewall spot... I'll even post a pic of the master cylinder, thanks though.

 

[jramos]

@ mud4feet, did you replace the master cylinder??? Because per the diagram it shows it as master cylinder/ power booster.

 

[mud4feet]

@ mud4feet, did you replace the master cylinder??? Because per the diagram it shows it as master cylinder/ power booster.

No, just replaced the booster. The master cylinder just bolts to it and can be moved out of the way to get the booster out.

 

[jramos]

Cool, im gonna check it out..

 

[jramos]

Know where I can locate any pics or diagrams on the booster removal?? Will I have to break open any brake lines to the system or is booster removal not affect the brake lines? Thanks in advance.

 

[mud4feet]

I cant remember if I you tubed it or if I used my Haynes Manual. But no, you dont have to remove any brake lines. Theres just enough room to move the master cylinder (brake lines intact) out of the way and get the booster out. If memory serves, theres 3 bolts that hold it to the firewall and maybe a connection to the pedal that you have to remove. Its really not too bad.

 

[jramos]

Dealer item???

 

[mud4feet]

No, I think I got mine from AutoZone.

 

[jramos]

Called checkers and they said they weren't showing the abs equipped option for the part, im assuming that it is smaller than the master cylinder.

 

[jramos]

I have noticed the booster pump and motor that is mounted under the hood, passenger side firewall that chargers the abs system now runs continuously instead of cycling on and off like it used to prior to this problem occuring?????

 

[SteelHeadz]

I have noticed the booster pump and motor that is mounted under the hood, passenger side firewall that chargers the abs system now runs continuously instead of cycling on and off like it used to prior to this problem occuring?????

Sounds like the pump relay is stuck closed. Either the module or the relay needs to be replaced. Disabling the pump by pulling the fuse should keep the pump motor from burning up. Your base brakes should remain functional however you will not have the aid of the ABS in case of a panic stop and brake lock up condition.

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[jramos]

Thanks for all the help, I figured out that by pulling the fuses and disabling the abs system altogether, no longer stalls out the engine. I'm back to old school brakes but at least im back on the road, a little whiter knuckles, lol but its all good jeepin'again....

Thanks again,
John.R