Recent Topics
Cloning a Lexus key
by Nayov - 08/23/19 04:23 PM
2011 GMC Acadia Shock/Strut Replacement
by panthermike - 08/23/19 03:49 PM
Confusion on oil to use on BMW 328i 2010
by goldenjava - 08/23/19 03:21 PM
Oil Confusion for 2010 BMW 328i
by goldenjava - 08/23/19 03:16 PM
ProSelect 27356 cut open
by Sayjac - 08/23/19 03:04 PM
Electrolux - Dryer reliability warning.
by pezzy669 - 08/23/19 02:37 PM
Microfiber Towels for different applications?
by Quattro Pete - 08/23/19 01:53 PM
Coated vs. painted rotors
by atikovi - 08/23/19 01:13 PM
New spark plugs, occasional misfire
by avacado11 - 08/23/19 12:34 PM
clean or replace o2 sensor?
by bionictony - 08/23/19 12:15 PM
Supertech equivalent
by Bettez88 - 08/23/19 12:06 PM
Federated OF Now Made in China
by Mr_Luke - 08/23/19 11:47 AM
Sourcing Particular Brembo Rotors
by RamFan - 08/23/19 11:22 AM
Intermittent Braking Vibration?
by Gebo - 08/23/19 10:59 AM
Northrop B-2 Spirit - First Cockpit Video
by john_pifer - 08/23/19 10:36 AM
ADBV Design - MANN Filter
by LeoStrop - 08/23/19 10:25 AM
"MYSTERY Oil" - 320 ppm Zinc
by Linctex - 08/23/19 10:20 AM
Thoughts on Time v Mileage
by BISCUT - 08/23/19 10:04 AM
Shocks / Struts
by WyrTwister - 08/23/19 08:04 AM
Newest Members
goldenjava, Spuzzum, ta249, bobsauto62, Ramz
69044 Registered Users
Who's Online Now
89 registered members (4WD, 2015_PSD, Anduril, A_Harman, ARCOgraphite, 10 invisible), 2,254 guests, and 38 spiders.
Key: Admin, Global Mod, Mod
Forum Statistics
Forums67
Topics293,700
Posts5,045,168
Members69,044
Most Online3,532
Jul 30th, 2019
Donate to BITOG
Print Thread
Hop To
Compressing pistons #4114399 06/03/16 05:13 PM
Joined: Nov 2007
Posts: 3,996
M
mjoekingz28 Offline OP
OP Offline
M
Joined: Nov 2007
Posts: 3,996
Let us say I am doing a front brake job on a regular car. I remove the caliper and pull the pads, THEN I unscrew the bleeder and push the piston in and then put it back like new so the new, full pads will fit the rotors.


My question is will I run into problems with fluid contamination, air in the system, or anything else that I cant think of right now?

Re: Compressing pistons [Re: mjoekingz28] #4114402 06/03/16 05:15 PM
Joined: Oct 2005
Posts: 11,641
D
d00df00d Offline
Offline
D
Joined: Oct 2005
Posts: 11,641
Yes. You'll get a tiny bit of moisture in the brake fluid and the system will have to be bled.


2008 BMW M3 Sedan 6MT
Re: Compressing pistons [Re: mjoekingz28] #4114403 06/03/16 05:18 PM
Joined: Dec 2013
Posts: 495
D
DSparks Offline
Offline
D
Joined: Dec 2013
Posts: 495
Shouldnt be that much of an issue as long as it didnt get any air in the caliper with the bleeder open....I usually use a big [censored] c-clamp to push the piston in and do it without opening the bleeder....

Re: Compressing pistons [Re: mjoekingz28] #4114411 06/03/16 05:28 PM
Joined: Jul 2012
Posts: 2,630
F
Falken Offline
Offline
F
Joined: Jul 2012
Posts: 2,630
When I did my Honda Fit brakes 20,000km ago (I also learned this in Auto Mechanics from a teacher):

Unscrew the bleeder before you push in the piston, this prevents copper oxide and gunk from being forced back into your ABS pump.

If you gravity bleed when you are done, with a vinyl hose attached, your brakes will be great.

If you can hit the brakes on gravel to cycle the ABS pump afterwards as well, you will have solid, firm brakes.

Re: Compressing pistons [Re: mjoekingz28] #4114442 06/03/16 06:30 PM
Joined: Nov 2011
Posts: 5,250
R
Rolla07 Offline
Offline
R
Joined: Nov 2011
Posts: 5,250
No need to unscrew the bleeder, save the hassle and just push in the piston.


2007 Corolla Red Pearl 155k miles
PP 0w20 & ST 4967
2015 Toyota Venza Parisian Blue Pearl 25k miles
TGMO 0W20 & OEM filter

Re: Compressing pistons [Re: mjoekingz28] #4114484 06/03/16 07:36 PM
Joined: Nov 2008
Posts: 14,197
S
supton Offline
Offline
S
Joined: Nov 2008
Posts: 14,197
In years past I would just push back the piston. No ABS back then. Today, I'd think it'd have to be a very large piston to drive fluid all the way back to the ABS pump. Might as well try to crack the bleeder. I don't think just cracking the bleeder will get air in, not unless if the piston were somehow pulled out in the process, or you waved the caliper around extensively with the bleeder cracked--I'd hold it steady while pushing in, then tighten back down while it's still in the same spot.


2011 Toyota Camry, base, 2.5L/6MT, 187k, hers
2010 Toyota Tundra DC, 4.6L/6AT, 153k, ours
1999 Toyota Camry LE, 2.2L/4AT, 209k, his
Re: Compressing pistons [Re: mjoekingz28] #4114485 06/03/16 07:37 PM
Joined: Dec 2013
Posts: 3,509
C
clinebarger Offline
Offline
C
Joined: Dec 2013
Posts: 3,509
Never push the funky old Brake Fluid that is in your Calipers back through the ABS & Master cylinder.

Open the bleeder, Push the piston in, Install your Pads & reinstall the Caliper, Pump the brake pedal a couple times, Open the bleeder & whatever air is in the caliper will gravity bleed out.


2001 Chevy Camaro L92/4L80E
2006 Chevy 2500HD LBZ/Allison 1000
2010 Toyota Corolla 2ZR-FE/U341E
2000 Toyota Avalon 1MZ-FE/A541E
Re: Compressing pistons [Re: mjoekingz28] #4114516 06/03/16 08:15 PM
Joined: Aug 2015
Posts: 133
X
Xrs2zz Offline
Offline
X
Joined: Aug 2015
Posts: 133
I cracked the bleeder before pushing the piston back, but I attached a tube to the bleeder first.

That way no air got back in because the tube was filled with old fluid and I closed the bleeder after the piston fully retracted. I have a nice firm pedal and it's been 3 months since I did the brakes.

I did a full fluid exchange last year, so I didn't bother bleeding the fluid after I was done.


2003 Toyota Matrix Xrs-207k Miles
Previous Thread
Index
Next Thread

BOB IS THE OIL GUY® Powered by UBB.threads™