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  #1  
Old 07-04-2020, 01:58 PM
Grom
 
Join Date: Mar 2020
Location: San Diego, CA
Posts: 261
Brake Bleeding Problems

Hi all,

I am really struggling to bleed my brakes, and could use some help. (I have never bled brakes before)

I replaced my rear rotors, calipers, pads, and soft lines. Rear passenger side bled with a mityvac ok. Now I am on the other side, and can't figure out what's happening.

I pump it up to 15-20" with the valve closed, it holds vacuum. Then I BARELY crack the valve and I get bubbling rapid drops in pressure, as well as burbling in the mitvac catch-cup, but I'm not really pulling much fluid.

I've tried PTFE tape and grease many times, but that doesn't fix it.
Additionally, the brake line I just installed isn't leaking at all, so I don't think that's it.

Pedal feels firm.
Newb question, do I have the brake reservoir open or closed during this process?

Help! I've been struggling for 2 hours...

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  #2  
Old 07-04-2020, 02:21 PM
Registered User
 
Join Date: Sep 2001
Posts: 1,557
Calipers are side specific and can be put on the wrong sides. Are both bleeder screws at the top of the caliper?

Is the reservoir full of fluid?

Did the reservoir run dry?
If yes it can take a lot of bleeding to get the air out.

Cap on or off? On, but try this, leave it off fill the reservoir, open the bleeder a lot, wait a few minutes to see if it will gravity bleed. It should. Raising the front of the car would help gravity bleeding. If it gravity bleeds follow up with a thorough bleed. I don't like mityvac methods, prefer pressure bleed first, then pump the pedal next.

Good luck!!!
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  #3  
Old 07-04-2020, 02:31 PM
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Join Date: Sep 2013
Location: Alhambra California
Posts: 2,799
Good point to ensure that the calipers are installed correctly. Also, begin your bleeding procedure at the right rear caliper, then the left rear, right front, and finally left front. There are times when the master cylinder will need to be removed and bench bled. Bench bleeding the MC involves removing the master cylinder, clamping it in a vise, and pumping the Master cylinder pistons as if stepping on the brake pedal. It is best while bench bleeding, to fashion tubes that lead from the discharge ports back into the reservoirs. Make sure to keep the reservoirs full while bench bleeding. The brake reservoir lid may be left off while bleeding. Brake fluid is murder on auto paint. If you spill brake fluid on your paint, rinse with lots of water immediately. Do not attempt to wipe off. The paint will be wiped off too.
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  #4  
Old 07-04-2020, 02:33 PM
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Join Date: Sep 2006
Location: Middle TN
Posts: 4,004
How are you connecting the bleeder? I now use pressure via a pressure bleeder connected to a spare master cylinder cap.

I simply connect, pump up the pressure, open the bleed valve and pull the trigger.

My alternate method is the old have a helper pump the brake pedal and hold while I open the valve. This has worked for years on multiple vehicles and was taught by my father in law almost 50 years ago.

Pressure bleeding is easier and you don't need a helper. You can even set the level in the master cylinder by having the tube extend into the master cylinder to the height you want. Release the pressure and the bleeder will siphon back into the main container and stop when fluid is even with the end of the tube.
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  #5  
Old 07-04-2020, 02:35 PM
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Join Date: Sep 2006
Location: Middle TN
Posts: 4,004
Yes, master needs to be bench bled but only if it's new and this is the 1st time installed.
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  #6  
Old 07-04-2020, 02:56 PM
Registered User
 
Join Date: Sep 2013
Location: Alhambra California
Posts: 2,799
Unfortunately I have needed to bench bleeding a “not new” master cylinder in the past. A pressure bleeder doesn’t make the job a lot more manageable.
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  #7  
Old 07-04-2020, 03:03 PM
Grom
 
Join Date: Mar 2020
Location: San Diego, CA
Posts: 261
Calipers are installed correctly, and the master cylinder never ran dry.
I'm conecting to the bleeder nipple via a very tight hose, it works well.

At this point, I am just pumping and pumping and the pressure is going down slowly and I am getting all air, just a tiny bit of fluid - a mist.

If I didn't bleed the other side properly, would that cause this issue?
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  #8  
Old 07-04-2020, 03:06 PM
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Join Date: Sep 2001
Posts: 1,557
Try gravity bleeding
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  #9  
Old 07-04-2020, 03:08 PM
Grom
 
Join Date: Mar 2020
Location: San Diego, CA
Posts: 261
Quote:
Originally Posted by Sugar Bear View Post
Try gravity bleeding
I attached a line to the valve, then ran to a bottle, then waited 10 minutes and saw nothing...
Where does the bottle go?
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  #10  
Old 07-04-2020, 03:09 PM
Registered User
 
Join Date: May 2008
Posts: 217
Quote:
Originally Posted by Junkman View Post
How are you connecting the bleeder? I now use pressure via a pressure bleeder connected to a spare master cylinder cap.

I simply connect, pump up the pressure, open the bleed valve and pull the trigger.

My alternate method is the old have a helper pump the brake pedal and hold while I open the valve. This has worked for years on multiple vehicles and was taught by my father in law almost 50 years ago.

Pressure bleeding is easier and you don't need a helper. You can even set the level in the master cylinder by having the tube extend into the master cylinder to the height you want. Release the pressure and the bleeder will siphon back into the main container and stop when fluid is even with the end of the tube.

Just do this and report back. Yes, these guys are all giving you good advice, however the vacuum bleeding at the caliper is usually just a miserable method. It “works” but not necessarily really well. Pedal bleeding, even alone is easier. If you got a firm pedal, your calipers are on the correct side - it’s practically impossible to get a firm pedal with the rears mixed up
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  #11  
Old 07-04-2020, 03:43 PM
Registered User
 
Join Date: Sep 2001
Posts: 1,557
Fill the reservoir, leave the cap off, attach a tube from the bleeder to a catch jar, open the bleeder a lot and wait. This method may get you started toward working with the Mityvac. As others have stated, pressure bleeding is the best method and it's an easy one person job.

Good luck!!!
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Does a Caddy stretch? No, but a Mercedes bendz.
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  #12  
Old 07-04-2020, 04:03 PM
Grom
 
Join Date: Mar 2020
Location: San Diego, CA
Posts: 261
I’d love to pressure bleed, but I don’t have the equipment needed. Buying everything means I might as well have a mobile mechanic come and do it for me.

I tried the two person method with my wife.
Passenger side I started to get fluid, but then it was all air. Switched to the other side, and in getting nothing, no bubbles no fluid at all.
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  #13  
Old 07-04-2020, 04:16 PM
wrench dropper
 
Join Date: Oct 2014
Location: very very very Nor-Cal
Posts: 200
I installed "speed bleeders" on all 4 calipers on my 300TD and it makes bleeding the calipers a super easy, super fast, one person job.
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  #14  
Old 07-04-2020, 04:25 PM
Grom
 
Join Date: Mar 2020
Location: San Diego, CA
Posts: 261
Another observation:
When the brake is pressed, and the valve is open, it doesn’t feel any softer than when the valve is closed.
Shouldn’t the pedal basically go to the floor if one of the bleeder valves is open?
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  #15  
Old 07-04-2020, 05:01 PM
Registered User
 
Join Date: Feb 2019
Posts: 175
The master cyl. reservoir can have more than two sections,and very hard to see fluid level
in most rear section.Must fill all most to very top to get the rear most to fill,and must refill a number of times.
Secondly master can have swollen rubber cups not allowing complete uncovering of fill hole to rear brakes.
Caution: when bleeding from pedal,never push pedal down further than normal,can push piston cups in to unclean area than when piston is released debris keeps rubber
from sealing,just lost the master.
Proper way to bleed with helper,pump up,tell person (ok) pops open bleeder no more than one second,tells healper again which than lets pedal off,for at least 3 seconds
again pumps ,repeat.

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