Any mechanics here?

PropThePolecat

PropThePolecat

Joined
Jan 31, 2009
Messages
3,292
Hey guys

When you change brakepads on your car, you have to push the brake piston back with a C-clamp, before you remount the caliper, so the whole brake-caliper with the new pads will be able to fit on the rotor.

My question is this: do you have to open the master cylinder cap, before you push the piston back?

Thanks
 
No,
take the old brake pad and lay it across the piston to'
give you a place to clamp the clamp
then squeeze it in

(i am not a mechanic,but have done MANY pad changes :) )
 
I have always taken the cap off of the master cylinder. The fluid that you are forcing out of the calipers has to go somewhere. When you compress the caliper, the fluid level in the master cylinder will rise, I use an old turkey baster to take some of the fluid out so it doesn't pour over the side.

Bruceter
 
Hmmm, I wasn't going to post in this thread, but it's right up my alley of 38 years bending wrenches. So, technically one is supposed to attach a flexible tube to the bleeder valve, affix a catch vessel, open the bleeder and compress the piston. This is done to eliminate pushing contaminates back up the line, ABS pump and master cylinder.

One should purge the brake fluid every couple of years to remove "moisture" as brakes do not like water......and ABS pumps are very spendy. So are most of the components for that matter.

Just take your car to a good shop and have then use the BG power flusher. A little amount of money that eliminates a potentially huge expense.
 
orork said:
Hmmm, I wasn't going to post in this thread, but it's right up my alley of 38 years bending wrenches. So, technically one is supposed to attach a flexible tube to the bleeder valve, affix a catch vessel, open the bleeder and compress the piston. This is done to eliminate pushing contaminates back up the line, ABS pump and master cylinder.

One should purge the brake fluid every couple of years to remove "moisture" as brakes do not like water......and ABS pumps are very spendy. So are most of the components for that matter.

Just take your car to a good shop and have then use the BG power flusher. A little amount of money that eliminates a potentially huge expense.
Click to expand...

Agreed, this is the best way to do this, brake jobs are ok to do yourself if you know what your doin' and are mechanically inclined.

That said, if your really not sure, take it to a professional, it's not that expensive of a job, it's better than riskin' your life over a couple a hundred bucks.
 
Bruceter said:
I have always taken the cap off of the master cylinder. The fluid that you are forcing out of the calipers has to go somewhere. When you compress the caliper, the fluid level in the master cylinder will rise, I use an old turkey baster to take some of the fluid out so it doesn't pour over the side.

Bruceter
Click to expand...

just loosen the cap. i f-ed up my 82 stangs paint the first brake pad change. the fluid eats the paint right off the metal. of course that was a long time ago. but i did get the paint fixed at maaco.:thumbup:
 
Hi PropThePolecat -

No - leave it on.

As long as no mis-informed backyard mechanic has added brake fluid into the system, then when you retract the pistons, the fluid level will go back up to full and you are done.

However, I have done brake jobs for people and when I push the pistons back the master cylinder overflows - because the owner saw the fluid was not up to the full level and topped it off. The fluid level will go down as the brake material wears - this is normal and the M/C should NEVER be topped off. If the level gets too low, then you have a leak in the system.

Another note - some GM cars have a piston that needs to be screwed back to retract, it cannot be pushed back with a c-clamp - examples are the 96-98 Lumina etc.

Remember to put some disc brake grease on the sliders.

best regards -

mqqn
 
mqqn said:
Hi PropThePolecat -

No - leave it on.

As long as no mis-informed backyard mechanic has added brake fluid into the system, then when you retract the pistons, the fluid level will go back up to full and you are done.

However, I have done brake jobs for people and when I push the pistons back the master cylinder overflows - because the owner saw the fluid was not up to the full level and topped it off. The fluid level will go down as the brake material wears - this is normal and the M/C should NEVER be topped off. If the level gets too low, then you have a leak in the system.

Another note - some GM cars have a piston that needs to be screwed back to retract, it cannot be pushed back with a c-clamp - examples are the 96-98 Lumina etc.

Remember to put some disc brake grease on the sliders.

best regards -

mqqn
Click to expand...

See, this is why ya should leave it to the pros, when I do brakes, I have a routine I follow which covers all the points that have been addressed so far but I've been a mechanic and taking care of and building or rebuilding cars for 37 years.

Again, if you have even the slightest doubt about how to do this, (and it seems like ya do, otherwise ya wouldn't be askin' for advice on a knife site ;)) see a professional mechanic, hell most of 'em are nice enough to let you watch and you can learn how to do it the right way for your self.

Hope this helps.:thumbup:
 
Hi PropThePolecat -

No - leave it on.

As long as no mis-informed backyard mechanic has added brake fluid into the system, then when you retract the pistons, the fluid level will go back up to full and you are done.

However, I have done brake jobs for people and when I push the pistons back the master cylinder overflows - because the owner saw the fluid was not up to the full level and topped it off. The fluid level will go down as the brake material wears - this is normal and the M/C should NEVER be topped off. If the level gets too low, then you have a leak in the system.
Click to expand...

Exactly what i thought, cause its a closed system.

Another note - some GM cars have a piston that needs to be screwed back to retract, it cannot be pushed back with a c-clamp - examples are the 96-98 Lumina etc.
Click to expand...

It a Mitsu Colt im working on.

Remember to put some disc brake grease on the sliders.
Click to expand...

Ive already got the grease :thumbup:


Thanks for your input. Just for the record, i AM mechanically inclined (metalsmith by trade and worked as a maintenance tech for years), but its been years since i last did my brakes.
Times are tough right now and my finances are stretched to the limit, so im doing the simple maintenance jobs myself, like flushing the coolant, changing oil, replacing filters and changing pads. Jobs like that dont intimidate me, and IMO is something everybody should do themselves.

I refuse to pay 185$ :mad: for just the pads, when i can get them from a UK-based shop for 65$. I wont even bother to tell you what a mechanic takes for a pad swap over here on the continent.

otherwise ya wouldn't be askin' for advice on a knife site )
Click to expand...

This particular knifesite is my playground :D
 
Everything went fine, as soon as i had the wheel off, it all came back. :thumbup:

5106799959_3a5d75ca36_z.jpg


5107398850_3aba876c7f_z.jpg
 
Hi PropThePolecat -

Good deal!

It figures it would have to be wet out when you had to do this job. Oh well, good job and now you have saved a little cash you can use to get another knife!

best regards -

mqqn
 
fugawee said:
great job
but why isnt that safety pin inserted in the jack stand! ;) :D
(even if its the lower hole)
Click to expand...

Good eyes bro - Safety first :D! Its because my jack couldnt lift the car far enough up, so i could slide the jackstand in, so i had to pull the pin out so it would become abit shorter.
 
Bruceter said:
I have always taken the cap off of the master cylinder. The fluid that you are forcing out of the calipers has to go somewhere. When you compress the caliper, the fluid level in the master cylinder will rise, I use an old turkey baster to take some of the fluid out so it doesn't pour over the side.

Bruceter
Click to expand...
This is exactly the way that I do it as well (for the past 30 years), then top off at the end with fresh fluid. I also bleed every couple of years just in case.
 
You must log in or register to reply here.
Back
Top