engine almost stalls when pumping brakes

Flav

Member
:
2002 Mazda Protege 5
Last night i was doing a brake job and when we went to go bleed the brakes when i'd pump through brakes the car almost stalled each time and also my brakes feel semi spongy now. Would that be a bad master cylinder?
 
Ok, when bleeding the brake hydraulic lines...the engine should not be running. Key should not even be near ignition.
Was this a complete Brake component replacement? i.e; Pads, Rotors, Rubber Brake Hose & Calipers?
And if so, did you bleed all the lines/calipers in the proper order?
starting from Left Rear, then Right Rear. Then Right Front. And finally Left Front. Making sure to top off master cylinder reservoir in between, as to protect any air from being introduced into system. And if air did get into system...you know will find yourself bleeding the Master Cylinder. AND NEXT, bleeding out the ABS Control Module. The pedal could feel slightly different when all new components are installed...but not spongy or weak.
 
Flav,

It's a Vac Assisted brake system. Every time you pump the brake it alters the airflow in the manifold, the auto adjuster is probably trying to hold idle when you are pumping the crap out of a system that was not designed to have an epileptic foot on it.

Dont bleed the brakes with the engine on.

Flashing_box.gif
 
Last edited:
Flav,

It's a Vac Assisted brake system. Every time you pump the brake it alters the airflow in the manifold, the auto adjuster is probably trying to hold idle when you are pumping the crap out of a system that was not designed to have an epileptic foot on it.

Dont bleed the brakes with the engine on.


*Noted

I honestly had no idea of this, for future reference, Do NOT turn the car when bleeding the system? Just pump the brakes regularly?
You'll have to excuse me as I have been misinformed from 2 separate friends who both drive domestic trucks. Perhaps their system work differently.
 
All you will do is waste gas, the "Mark One Leg" is fully capable of providing the lever of effort to push 1 Ounce out of a little hose. Perhaps on a big truck it is required but in this case it is not part of the procedure.
 
Ok, when bleeding the brake hydraulic lines...the engine should not be running. Key should not even be near ignition.
Was this a complete Brake component replacement? i.e; Pads, Rotors, Rubber Brake Hose & Calipers?
And if so, did you bleed all the lines/calipers in the proper order?
starting from Left Rear, then Right Rear. Then Right Front. And finally Left Front. Making sure to top off master cylinder reservoir in between, as to protect any air from being introduced into system. And if air did get into system...you know will find yourself bleeding the Master Cylinder. AND NEXT, bleeding out the ABS Control Module. The pedal could feel slightly different when all new components are installed...but not spongy or weak.

Here's what we did yesterday.
Tried to do the mazda 626 rear swap out (did not work, the rotor rubbed up against the bracket, which came off a 626 as well)
So we returned all that s*** and grabbed all stock components.
Rotors and pads (calipers were fine)
Installed everything, but left the driver side E-brake cable out (it's sized to s***. Thought the caliper was siezed but when we removed everything it turned out to be the cable)
Once all that was put together we bled the brakes in the proper order (yes with the engine on..do'h)

Now when I drive, I have brakes, but they do seem slightly spongy. Or perhaps I'm just being anal about how stiff I want my brakes to be working.
 
All you will do is waste gas, the "Mark One Leg" is fully capable of providing the lever of effort to push 1 Ounce out of a little hose. Perhaps on a big truck it is required but in this case it is not part of the procedure.

Thanks Brian
 
It could be air or you are just being paranoid because it is newly fixed.

EDIT: Here is what you really want. No Pumping, it draws the fluid out at the caliper by force.

It is a Mityvac


resize
 
Last edited:
Very cool, no second person required to pump? Just hook it up to the caliber and let it do the work for you.
I may invest in one of these...seems like a great product to have for the future.
 
They are nice to have for brakes, but a must for bleeding the clutch which has no one way valve.

They are around $130.00 for this which is name brand. El Cheapo is a waste of money.
 
Flav,

It's a Vac Assisted brake system. Every time you pump the brake it alters the airflow in the manifold, the auto adjuster is probably trying to hold idle when you are pumping the crap out of a system that was not designed to have an epileptic foot on it.

Dont bleed the brakes with the engine on.

Flashing_box.gif

I had to have the engine running to bleed the brakes. Without it on, the pedal just became impossible to push...
 
Back