UPDATED: Changing my Brakes Quick question

[Kelemvor]

UPDATE:
OK, GOt the pads changed and had to take the top off the reservoir. Fluid came all out everywhere so I'm assuming the oil change place must top off the fluids for me when I go in. One pad was literally gone so there was a ton of extra fluid in there.

So, NEW QUESTION is, when I put everything back together, should I put the cap on, then press the brakes a few times, then release and put the cap back on again to relieve any pressure issues? Or does it not really matter as far as when and how to put the cap back on?


OLD QUESTION:
I'm putting new pads and rotors on my truck but am not (at this time) changing the fluid and such. (I'll do that when I have more time).

WHen I putthe new pads and rotors on, I can't get the pads/caliper on the rotors because they are now too tight. Since I'm not changing the fluid, what can I do?

Can I just take the cap off the brake fluid reservoir and will that relieve the pressure that I can push the piston back in further so I can make them all fit? And then just screw the reservoir cover back on when I'm done?

ANy other ideas?

Thanks.

 

[jlee]

Use a c-clamp to push the piston back in.

 

[OrganizedChaos]

if its a singe piston you can usually get by with a c-clamp. multiple pistions and you'll have to get a caliper spreader from the autoparts store

 

[JulesMaximus]

Originally posted by: CadetLee
Use a c-clamp to push the piston back in.

Stick a 2x4 in there if you can (or something thin and flat that won't score the piston in the brake caliper) and use that and a c-clamp to push the piston back in. Make sure you have the cover off the brake fluid resevior so the fluid will have someplace to go. You should syphon off some of the fluid or you'll have a mess to clean up.

Also, try not to damage the rubber ring around the piston or you'll have to rebuild the caliper.

 

[imported_LoKe]

+1 for some sort of clam. Also, some big-ass pliers will do it, just squeeze the piston slowly.

Originally posted by: JulesMaximus

Originally posted by: CadetLee
Use a c-clamp to push the piston back in.

Stick a 2x4 in there if you can (or something thin and flat that won't score the piston in the brake caliper) and use that and a c-clamp to push the piston back in. Make sure you have the cover off the brake fluid resevior so the fluid will have someplace to go. It will run out of the reservior also, this is normal...and messy.

Also, try not to damage the rubber ring around the piston or you'll have to rebuild the caliper.

It's not necessary to drain any fluid when compressing the piston.

 

[jlee]

Originally posted by: JulesMaximus

Originally posted by: CadetLee
Use a c-clamp to push the piston back in.

Stick a 2x4 in there if you can (or something thin and flat that won't score the piston in the brake caliper) and use that and a c-clamp to push the piston back in. Make sure you have the cover off the brake fluid resevior so the fluid will have someplace to go. It will run out of the reservior also, this is normal...and messy.

Also, try not to damage the rubber ring around the piston or you'll have to rebuild the caliper.

If he hasn't added fluid since the pads were changed, will it still run over? When we changed pads in my old Corolla, I don't think that happened..

 

[Kelemvor]

I'm using a clamp but I didn't take the cover off the reservoir. That was my main question on if I had to do that or not and it seems I do since there's too much pressure.

And since I'm not adding fluid, it better not flow over... But I guess we'll see. 🙂

 

[imported_LoKe]

Originally posted by: CadetLee

Originally posted by: JulesMaximus

Originally posted by: CadetLee
Use a c-clamp to push the piston back in.

Stick a 2x4 in there if you can (or something thin and flat that won't score the piston in the brake caliper) and use that and a c-clamp to push the piston back in. Make sure you have the cover off the brake fluid resevior so the fluid will have someplace to go. It will run out of the reservior also, this is normal...and messy.

Also, try not to damage the rubber ring around the piston or you'll have to rebuild the caliper.

If he hasn't added fluid since the pads were changed, will it still run over? When we changed pads in my old Corolla, I don't think that happened..

The fluid will be fine. Don't worry about it.

Originally posted by: FrankyJunior
I'm using a clamp but I didn't take the cover off the reservoir. That was my main question on if I had to do that or not and it seems I do since there's too much pressure.

And since I'm not adding fluid, it better not flow over... But I guess we'll see. 🙂

Don't open the reservoir.

 

[JulesMaximus]

Originally posted by: LoKe
+1 for some sort of clam. Also, some big-ass pliers will do it, just squeeze the piston slowly.

Originally posted by: JulesMaximus

Originally posted by: CadetLee
Use a c-clamp to push the piston back in.

Stick a 2x4 in there if you can (or something thin and flat that won't score the piston in the brake caliper) and use that and a c-clamp to push the piston back in. Make sure you have the cover off the brake fluid resevior so the fluid will have someplace to go. It will run out of the reservior also, this is normal...and messy.

Also, try not to damage the rubber ring around the piston or you'll have to rebuild the caliper.

It's not necessary to drain any fluid when compressing the piston.

If you don't, the piston will just pop back out when you release the c-clamp.

 

[jlee]

Originally posted by: JulesMaximus

Originally posted by: LoKe
+1 for some sort of clam. Also, some big-ass pliers will do it, just squeeze the piston slowly.

Originally posted by: JulesMaximus

Originally posted by: CadetLee
Use a c-clamp to push the piston back in.

Stick a 2x4 in there if you can (or something thin and flat that won't score the piston in the brake caliper) and use that and a c-clamp to push the piston back in. Make sure you have the cover off the brake fluid resevior so the fluid will have someplace to go. It will run out of the reservior also, this is normal...and messy.

Also, try not to damage the rubber ring around the piston or you'll have to rebuild the caliper.

It's not necessary to drain any fluid when compressing the piston.

If you don't, the piston will just pop back out when you release the c-clamp.

😕

I don't recall that happening. It has been a while, though.

 

[JulesMaximus]

Originally posted by: CadetLee

Originally posted by: JulesMaximus

Originally posted by: CadetLee
Use a c-clamp to push the piston back in.

Stick a 2x4 in there if you can (or something thin and flat that won't score the piston in the brake caliper) and use that and a c-clamp to push the piston back in. Make sure you have the cover off the brake fluid resevior so the fluid will have someplace to go. It will run out of the reservior also, this is normal...and messy.

Also, try not to damage the rubber ring around the piston or you'll have to rebuild the caliper.

If he hasn't added fluid since the pads were changed, will it still run over? When we changed pads in my old Corolla, I don't think that happened..

Well, you could always syphon a bit of fluid out before so it doesn't overflow. That's probably the best thing to do actually. Then just top it up after you're finished with the brake job.

 

[imported_LoKe]

Originally posted by: JulesMaximus

Originally posted by: CadetLee

Originally posted by: JulesMaximus

Originally posted by: CadetLee
Use a c-clamp to push the piston back in.

Stick a 2x4 in there if you can (or something thin and flat that won't score the piston in the brake caliper) and use that and a c-clamp to push the piston back in. Make sure you have the cover off the brake fluid resevior so the fluid will have someplace to go. It will run out of the reservior also, this is normal...and messy.

Also, try not to damage the rubber ring around the piston or you'll have to rebuild the caliper.

If he hasn't added fluid since the pads were changed, will it still run over? When we changed pads in my old Corolla, I don't think that happened..

Well, you could always syphon a bit of fluid out before so it doesn't overflow. That's probably the best thing to do actually. Then just top it up after you're finished with the brake job.

Nope. The pressure will be fine and the piston will stay put.

 

[tfinch2]

Take the cap off the master cylinder take some brake fluid out with an old turkey baster, and use a c-clamp to compress the calipers. When you're done, just squirt the brake fluid back in.

If you have the proper amount of fluid, when you compress brake fluid will shoot out.

 

[JulesMaximus]

Originally posted by: LoKe

Originally posted by: JulesMaximus

Originally posted by: CadetLee

Originally posted by: JulesMaximus

Originally posted by: CadetLee
Use a c-clamp to push the piston back in.

Stick a 2x4 in there if you can (or something thin and flat that won't score the piston in the brake caliper) and use that and a c-clamp to push the piston back in. Make sure you have the cover off the brake fluid resevior so the fluid will have someplace to go. It will run out of the reservior also, this is normal...and messy.

Also, try not to damage the rubber ring around the piston or you'll have to rebuild the caliper.

If he hasn't added fluid since the pads were changed, will it still run over? When we changed pads in my old Corolla, I don't think that happened..

Well, you could always syphon a bit of fluid out before so it doesn't overflow. That's probably the best thing to do actually. Then just top it up after you're finished with the brake job.

Nope. The pressure will be fine and the piston will stay put.

And you've done this how many times on what kind of car?

I've done many brake jobs on my cars over the years and always had to compress the piston with a c-clamp and open the reservoir. I've done brakes on a few different Mustangs, a Toyota Tundra, an Isuzu Rodeo and some older cars I owned when I was in my teens/early 20s.

 

[imported_LoKe]

Originally posted by: JulesMaximus

Originally posted by: LoKe

Originally posted by: JulesMaximus

Originally posted by: CadetLee

Originally posted by: JulesMaximus

Originally posted by: CadetLee
Use a c-clamp to push the piston back in.

Stick a 2x4 in there if you can (or something thin and flat that won't score the piston in the brake caliper) and use that and a c-clamp to push the piston back in. Make sure you have the cover off the brake fluid resevior so the fluid will have someplace to go. It will run out of the reservior also, this is normal...and messy.

Also, try not to damage the rubber ring around the piston or you'll have to rebuild the caliper.

If he hasn't added fluid since the pads were changed, will it still run over? When we changed pads in my old Corolla, I don't think that happened..

Well, you could always syphon a bit of fluid out before so it doesn't overflow. That's probably the best thing to do actually. Then just top it up after you're finished with the brake job.

Nope. The pressure will be fine and the piston will stay put.

And you've done this how many times on what kind of car?

I've done many brake jobs on my cars over the years and always had to compress the piston with a c-clamp and open the reservoir. I've done brakes on a few different Mustangs, a Toyota Tundra, an Isuzu Rodeo and some older cars I owned when I was in my teens/early 20s.

Hmm, I guess you're right about that. I work on BMW's and Mercedes only, so there's a good chance they're different. I'll leave it to you then, since you've obviously been doing it a lot longer than I have.

 

[JulesMaximus]

Originally posted by: LoKe

Originally posted by: JulesMaximus
And you've done this how many times on what kind of car?

I've done many brake jobs on my cars over the years and always had to compress the piston with a c-clamp and open the reservoir. I've done brakes on a few different Mustangs, a Toyota Tundra, an Isuzu Rodeo and some older cars I owned when I was in my teens/early 20s.

Hmm, I guess you're right about that. I work on BMW's and Mercedes only, so there's a good chance they're different. I'll leave it to you then, since you've obviously been doing it a lot longer than I have.

I was just asking. Jeez. :roll:

If he can't get the piston far enough into the caliper I still suggest removing the cap to the reservoir and draining fluid out. I stand by this.

 

[DrPizza]

Originally posted by: JulesMaximus

Originally posted by: LoKe
+1 for some sort of clam. Also, some big-ass pliers will do it, just squeeze the piston slowly.

Originally posted by: JulesMaximus

Originally posted by: CadetLee
Use a c-clamp to push the piston back in.

Stick a 2x4 in there if you can (or something thin and flat that won't score the piston in the brake caliper) and use that and a c-clamp to push the piston back in. Make sure you have the cover off the brake fluid resevior so the fluid will have someplace to go. It will run out of the reservior also, this is normal...and messy.

Also, try not to damage the rubber ring around the piston or you'll have to rebuild the caliper.

It's not necessary to drain any fluid when compressing the piston.

If you don't, the piston will just pop back out when you release the c-clamp.

The piston will be fine... However, if the reservoir has been topped off while after the pads were worn thin,, it can result in the stuff squirting all over inside the engine compartment, rather than simply running over. Bad stuff for the paint inside. For that reason, he should loosen the cap.

 

[imported_LoKe]

Originally posted by: JulesMaximus

Originally posted by: LoKe

Originally posted by: JulesMaximus

Originally posted by: LoKe

Originally posted by: JulesMaximus

Originally posted by: CadetLee

Originally posted by: JulesMaximus

Originally posted by: CadetLee
Use a c-clamp to push the piston back in.

Stick a 2x4 in there if you can (or something thin and flat that won't score the piston in the brake caliper) and use that and a c-clamp to push the piston back in. Make sure you have the cover off the brake fluid resevior so the fluid will have someplace to go. It will run out of the reservior also, this is normal...and messy.

Also, try not to damage the rubber ring around the piston or you'll have to rebuild the caliper.

If he hasn't added fluid since the pads were changed, will it still run over? When we changed pads in my old Corolla, I don't think that happened..

Well, you could always syphon a bit of fluid out before so it doesn't overflow. That's probably the best thing to do actually. Then just top it up after you're finished with the brake job.

Nope. The pressure will be fine and the piston will stay put.

And you've done this how many times on what kind of car?

I've done many brake jobs on my cars over the years and always had to compress the piston with a c-clamp and open the reservoir. I've done brakes on a few different Mustangs, a Toyota Tundra, an Isuzu Rodeo and some older cars I owned when I was in my teens/early 20s.

Hmm, I guess you're right about that. I work on BMW's and Mercedes only, so there's a good chance they're different. I'll leave it to you then, since you've obviously been doing it a lot longer than I have.

I was just asking. Jeez. :roll:

If he can't get the piston far enough into the caliper I still suggest removing the cap to the reservoir and draining fluid out. I stand by this.

I wasn't being sarcastic. 😕
I've only been doing it for ~year.

 

[skyking]

Originally posted by: JulesMaximus

Originally posted by: LoKe

Originally posted by: JulesMaximus

Originally posted by: CadetLee

Originally posted by: JulesMaximus

Originally posted by: CadetLee
Use a c-clamp to push the piston back in.

Stick a 2x4 in there if you can (or something thin and flat that won't score the piston in the brake caliper) and use that and a c-clamp to push the piston back in. Make sure you have the cover off the brake fluid resevior so the fluid will have someplace to go. It will run out of the reservior also, this is normal...and messy.

Also, try not to damage the rubber ring around the piston or you'll have to rebuild the caliper.

If he hasn't added fluid since the pads were changed, will it still run over? When we changed pads in my old Corolla, I don't think that happened..

Well, you could always syphon a bit of fluid out before so it doesn't overflow. That's probably the best thing to do actually. Then just top it up after you're finished with the brake job.

Nope. The pressure will be fine and the piston will stay put.

And you've done this how many times on what kind of car?

I've done many brake jobs on my cars over the years and always had to compress the piston with a c-clamp and open the reservoir. I've done brakes on a few different Mustangs, a Toyota Tundra, an Isuzu Rodeo and some older cars I owned when I was in my teens/early 20s.

The cap need not be removed, it is vented. Unless fluid was added since the last change, it will not overflow.

The messy part you are talking about is the jet of fluid that shoots up out of the cylinder port straight up through the pool of fliud. If the cap is on, no worries.

Julius, you may have had a plugged or partially plugged vent that time the piston came back at you, or may have added enough fluid beteween brake jobs that it totally filled the master cylinder resevoir and had no where to go.

 

[JulesMaximus]

Originally posted by: LoKe

Originally posted by: JulesMaximus

Originally posted by: LoKe

Originally posted by: JulesMaximus

Originally posted by: LoKe

Originally posted by: JulesMaximus

Originally posted by: CadetLee

Originally posted by: JulesMaximus

Originally posted by: CadetLee
Use a c-clamp to push the piston back in.

Stick a 2x4 in there if you can (or something thin and flat that won't score the piston in the brake caliper) and use that and a c-clamp to push the piston back in. Make sure you have the cover off the brake fluid resevior so the fluid will have someplace to go. It will run out of the reservior also, this is normal...and messy.

Also, try not to damage the rubber ring around the piston or you'll have to rebuild the caliper.

If he hasn't added fluid since the pads were changed, will it still run over? When we changed pads in my old Corolla, I don't think that happened..

Well, you could always syphon a bit of fluid out before so it doesn't overflow. That's probably the best thing to do actually. Then just top it up after you're finished with the brake job.

Nope. The pressure will be fine and the piston will stay put.

And you've done this how many times on what kind of car?

I've done many brake jobs on my cars over the years and always had to compress the piston with a c-clamp and open the reservoir. I've done brakes on a few different Mustangs, a Toyota Tundra, an Isuzu Rodeo and some older cars I owned when I was in my teens/early 20s.

Hmm, I guess you're right about that. I work on BMW's and Mercedes only, so there's a good chance they're different. I'll leave it to you then, since you've obviously been doing it a lot longer than I have.

I was just asking. Jeez. :roll:

If he can't get the piston far enough into the caliper I still suggest removing the cap to the reservoir and draining fluid out. I stand by this.

I wasn't being sarcastic. 😕
I've only been doing it for ~year.

No problem. I'm not a mechanic by trade but I have been working on my own cars for about 20 years now. :beer:

 

[JulesMaximus]

Originally posted by: skyking
The cap need not be removed, it is vented. Unless fluid was added since the last change, it will not overflow.

The messy part you are talking about is the jet of fluid that shoots up out of the cylinder port straight up through the pool of fliud. If the cap is on, no worries.

Julius, you may have had a plugged or partially plugged vent that time the piston came back at you, or may have added enough fluid beteween brake jobs that it totally filled the master cylinder resevoir and had no where to go.

Perhaps. These were mostly older cars and that may have been the case. It's been a while since I've done any work on my own car.

If the OP is having trouble with it though this is a good solution.

 

[Kelemvor]

Updated original question since I got everything new put on...

 

[tfinch2]

Originally posted by: FrankyJunior
So, NEW QUESTION is, when I put everything back together, should I put the cap on, then press the brakes a few times, then release and put the cap back on again to relieve any pressure issues? Or does it not really matter as far as when and how to put the cap back on?

Proper procedure is to now bleed the lines, but you can just put the cap on a drive. Let the car roll and pump the brakes until they become firm.

 

[imported_LoKe]

Ah, you've been going in for oil services instead of oil changes, haven't you? A service includes a quick inspection, topping of fluids, etc. An oil & filter change is just that; oil and filter.

 

[CFster]

1. You don't have to open the cap on the resevoir when compressing a caliper piston, unless the resevoir is almost full (in which case it will either push past the cap, or in some RARE cases stop the caliper piston - that is provided your other calipers are already installed with fresh pads and have no free movement). As a matter of fact, you should never fill the master to the top anyway, as brake fluid expands when it's hot - your brakes could literally apply themselves when the system is hot (the fluid has nowhere to go).
2. You might have a stuck caliper. If all else fails open the bleeder and try compressing it - if it still doesn't budge throw the caliper away.
3. You might have the wrong pads and/or rotors installed.
4. If you're trying to compress a REAR caliper in, sometimes they have to be SCREWED in.
5. If you're trying to compress a REAR caliper in, sometimes they have an e-brake lever - which if it isn't all the way in the release position will prevent the piston from going all the way in.
6. There is no way a caliper piston will "spring back out" after compressing it unless somebody steps on the brake pedal.
7. You could have one of the new inboard pads cocked in the caliper, preventing movement.

Is the face of the caliper piston flush with the caliper housing itself? Is the boot folded evenly around it - flush as well?

IMO, you just have haven't put enough elbow grease to it, or have a stuck caliper, or the wrong parts installed.

What kind of truck is it?

BTW, I'm an ASE service manager. I've been fixing cars for 20 years (of all makes).

-CF