99 Master Clyinder question

[tempfixit]

Nieghbor has a 99 that he has to pump the brakes to get the proper brakes.

He claims to having bleed the brakes but may be needed to do again.

I have tried parts stores and GM dealer for master clyinder seal repair kit
without any luck, not available.

Does anyoone by chance know the GM parts number for the kit??? Then possibly I could find the kit on rearcounter.com.

Thanks

[gmtech1]

GM hasn't offered a reduild kit for master cylinders for several years. If it's bad it will need replaced.

[tempfixit]

Originally Posted by gmtech1

GM hasn't offered a reduild kit for master cylinders for several years. If it's bad it will need replaced.

I thought maybe someone had the old part number.

Shame a person cannot fix something the old fashioned way anymore.

thanks

[FISH96]

are you absolutely sure the master cylinder is at fault?
you state, "he says he bled the brakes.' why?
has anyone checked for leaks? at this age the malibu is notorious for leaking brake lines(steel not the hoses)because of rusting. this occurs where the line passed through the plastic holders. there are a number of them. inspect them all. at this age the hoses should be inspected also.

the master cyl rebuild kit is not available because the bore is aluminum. once pitted it is difficult to obtain a proper seal therefore the entire unit should be replaced (tech11). those master cyl rebuilt by a rebulider will sometimes have a steel sleeve placed in the bore for sealing purposes.

some folks do not agree with this: the brake fluid should be flushed/changed like any other working fluid in the automobile. i use three years or less. this practice will also diminish problems with the ABS system. these are my thoughts.

[tempfixit]

Originally Posted by FISH96

are you absolutely sure the master cylinder is at fault?
you state, "he says he bled the brakes.' why?
has anyone checked for leaks? at this age the malibu is notorious for leaking brake lines(steel not the hoses)because of rusting. this occurs where the line passed through the plastic holders. there are a number of them. inspect them all. at this age the hoses should be inspected also.

the master cyl rebuild kit is not available because the bore is aluminum. once pitted it is difficult to obtain a proper seal therefore the entire unit should be replaced (tech11). those master cyl rebuilt by a rebulider will sometimes have a steel sleeve placed in the bore for sealing purposes.

some folks do not agree with this: the brake fluid should be flushed/changed like any other working fluid in the automobile. i use three years or less. this practice will also diminish problems with the ABS system. these are my thoughts.

I have not inspected the lines or hoses my self, Like I said he claims to have bleed the system. I have inspected the fluid level a couple of times and does not seem to have any fluid loss. From what I could see when the brakes were pumped it looked like air bubbles in the resorvoir.

I did not think of the clyinder being made of aluminum, makes sense.

I will help him bleed the brakes again and see what happens.

thanks

[Tech II]

If he presses hard on the brake pedal, does it slowly go to the floor?

Also check the rear of the M/C where it mates with the brake booster, for brake fluid.....