Projects Brake bleeding is making me crazy

I had an off topic pickup that the master cylinder started leaking a little. Never had trouble with the brakes. Replaced the master with a new one and couldn't get it bled. Got a second one and couldn't bleed that either. I couldn't believe I got 2 bad ones so I put the original back on and it bled easily so I got a third new one and it worked.

 

I have often used a system I picked up from an aircraft mechanic several years ago. I use a quart capacity pump style oil can filled with brake fluid and a section of clear hose attached to the flex tube tip. I start at the customary 'farthest from the M/C' bleeder, usually the right rear. I attach the hose to the bleeder, loosen the connection at the 'T' for the rear lines, loosen the bleeder, and pump fluid into the wheel cylinder/caliper until air free fluid exits the 'T'. Tighten the "t" fitting, close the bleeder and proceed to the left rear bleeder. loosen the brake fitting at the M/C, loosen the blleder and pump. Repeat on front brake wheel cylinder/calipers. Has worked for me several times.

Ray

 

I always was a fan of my Mighty Vac, until it quit "Vac'ing", so years ago I'd bought a large vacuum tank I turne into an air compressor. So I rigged up a motor to run the vacuum pump, I used the MV cannister thing, and fire up the pump, get 16-17inches of vacuum on the bleeder, crack the bleeder...and repeat till no bubbles.

Need to find a smaller vacuum pump setup, or put this one on castors.

 

Collapased flex hoses will also create a lot of problems . People are pretty good about changing the front flex hoses but usually over look the rear one

 

All good points and valid.

Sometimes when I have a new system ( master, lines ,calipers, wheel cylinder etc.
Air can get trapped in the lines etc.

What I do is bleed in sections...., start st the fittings at the master pump and crack the lines untill you see no air, then move to the next closest component or fitting etc. All the way down the system to the furthest point away ( ie right rear is the last one done.)
Then bleed at the bleeders like normal.

Sometimes stuck bleeding a car for way to long, then do this and done.

A pressure bleeder is the cats ass
A vacuum bleeder is a very close second both are super convenient and make bleeding brakes and clutch slaves etc a breeze.

 

I only use digital timepieces, now what?
Bob

 

I have given up on pressure bleeders, and made a vacuum bleeder. It not only solved all my problems, but I can bleed the brakes in 1/10th of the time it used to take me. This gets around the problem of having residual pressure valves in the system.
Bob

 

Since my parents are European this isn't unusual to me. Never been up where you are though.

 

I've shared my new learned procedure on the HAMB many times. I asked a friend (was a HAMBer but got kicked off for doing nothing) to help me bleed brakes he came over and I pumped and pumped worked had fluid all over and finally said …. here let me show you how to bleed brakes. And I did.. easy! use a large animal syringe and a short 1/4" hose. NO BENCH BLEED NO PUMPING NO AIR FAST EASY NO MIGHTY VAC NO JARS! done

 

tell us more please

 

Nicely asked. Many of you live in a rural area, or know of a veterinary . buy the size "BIG" syringe I'm not sure how many cc. next a piece of 1/4" rubber hose total investment.... $8-$10 ease of operation.... priceless.
fill the syringe w/ fluid go to bleeder further from the MC.open the bleeder and pressure the line past the "T" close bleeder. go to the other side this time pressure the line into the MC. go to the front do the same. top off the master cylinder. Clean up.

 

I always learn from HAMB. Never knew snugging up the drum brakes would help and now I have a good pedal on the old beast! Thanks again, Guys!

 

What "T" I'm confused. I like your thinking.
Terry aka dirt t

 

My two cents- if the master cylinder is on the firewall, there is such a thing as gravity bleeding if you work alone. It can take a while (maybe 1/2 hour) for the farthest bleeder to start dripping and after that it goes quicker. You can open them all and just keep an eye on things and close them off when the drip starts. Make sure the MC reservoir doesn't go dry in the process. If you have a helper, a quickie bleed can be done by cracking a bleeder maybe a half a turn and hold your finger over the end and let the pumping begin, preferably slowly to minimize the mess. Your finger acts as a check valve to prevent sucking much air back in. You'll feel and hear when the bubbles stop coming. After doing all 4 wheels, go back and start over. Tap each cylinder/caliper lightly a bunch of times to send remaining bubbles to the top, helper holds the pedal down while you crack and retighten the bleeder. Do this maybe 3 times on each wheel until you're sure there's no more air. Can't overstress the importance of the helper NOT releasing the pedal until the bleeder is tightened and NOT running the MC dry, check it often.

 

well, you have one line running from the master to the rear end. but you have 2 wheel cyl. so there is a "T" in the line. If you don't have a T in the line we may have found your brake problem

 

I've done a bunch of race car brake systems and they can be a pain. I've never used an special tool for bleeding. get a vinyl hose and a jelly jar. I did the brakes on my 28 this spring with my 8 year old. took two minutes to teach him what we were doing, why and how I wanted him to press the pedal. he was very happy to help and learned something.
start at farthest wheel
put wrench on bleeder and connect tube, insert into jelly jar
open bleeder
have helper slowly push the pedal to the floor and hold it (2-3 second push)
close bleeder, tell helper to slowly release pedal
repeat until no more air and or fluid runs clear. (both are important btw)
hit each corner and you are done.

as for the guys who say to adjust brakes first, that's a GIVEN! I took a 1936 ford vintage modified out last weekend at monadnock speedway in NH. I hit the pedal and it went right to the floor! went around and spent the 5 minutes to adjust the 42-48 ford style brakes and she had a great pedal. unfortunately it lost a u joint and ripped off the tailshaft in the first two laps of practice.

 

We use a power bleeder.

Sent from my Moto Z (2) using The H.A.M.B. mobile app

 

So by using a syringe and pushing the brake fluid from RR to "T" to LR, to M/C. how is the fluid getting past the 10lb. residual valve if installed? Same in front with a 2lb. res. valve?

 

Being a farmer, I have also used large syringes, 100ml/cc, and also drench guns (new), for easy bleeding of OT vehicles.
Seems to work ok.

 

I have had the same problem a few years ago. Spent 6 weeks on and off trying to get a good pedal. Every time they seemed to bleed fine with no air and after about 5 mins the pedal would go spongy again. Eventually found brand new wheel cylinders where drawing in air (no leeks), changed them and got great pedal first time.

Sent from my 9001X using The H.A.M.B. mobile app

 

Yes I've lived that. tough to find without a leak! I even asked the HAMB think tank for help on that one! many have said impossible but I had that on 2 cars. I often say can fix anything but a broken heart.... wife says AND BRAKES!

 

I can't wait till I have some wierd brake bleeding issue come here and try one of theses other systems and processes I hear about.

 

Well...….idontknow, theory..the valves hold 10lbs. of fluid but does have to flow back or my brakes would never release??????? SOOoo fluid will go through them. Less technical , it works?

 

Sadist...

 

Not really, just no reason to try them out but I want to.

Seems everything here bleeds fine and right as rain as long as the hard parts are doing what they are supposed to do. We do get bad parts right out of the box sometimes and that's frustrating. We find a slid over shuttle valve that have caused others to curse the devil but those are quickly resolved. Once in a while we find a brake like ran in an up and over configuration that causes air traps so we correct those and we are sure not to run them that way. Sometimes we even have to take a caliper loose and physically put the bleeder straight up, block the pads, bleed them and then reattach the calipers. But I must admit, we always do bleeding with 2 people.

 

I asked my buddy's shop to bleed my brakes, didn't watch it, but I'm thinking they tweaked the M/C push rod and now the brakes need to be pumped one time.

I've got disc brakes on all 4 corners, they also told me it could be from the M/C being lower than the wheel cylinder bleeders. I've got it on the lift, will check the M/C push rod.

Also was told that there is an adjustment on the rear park brake that can be made, but mine don't have rear park brakes.

 

You should not have to pump them to get a pedal.
With the master lower than the bleeders on discs there should be a 2lb residual pressure valve inline close to the master. All drum brakes reguardless of the height of the master need a 10 lb residual pressure valves. Many drum type master cylinders have these built in.

Rear discs have one of 3 set ups for the parking brake. A small internal mechanical drum brake or a cable attached to the calipers to mechanically clamp the pads. Neither one of those will have any relation to the hydraulics side of it. The 3rd is an electric activation of the parking brake.

 

The rear calipers from GM that the caliper is the parking brake, the adjustment does affect the hydraulic action. The only way they adjust (ratchet action) is when the parking brake is applied. The ratcheting of the park brake takes up the space the wearing of the pads creates. If the pads have worn down a bit and the parking brake has not been used to compensate, you will need to pump the brake pedal to move the caliper piston. Just like worn brake shoes on drums.

 

70% or more of vehicles in the Cleveland area have NEVER moved or used their parking brake, they are rusted solid. The rear brakes work fine.

The GM 82-88 delco morain calipers (J65) rear brake option indeed adjusted by having the E brake cycled but they didn't operate as designed in real world situations and were recalled.

 

You mean gm’s high maintenance brake system ?! Lol
Did a lot of CPR ( calipers, pads and rotors) on those shitters when they were on the road.

Not that is matters to what we work on but a few Japanese cars do have adjusters on the rear calipers to take up pad ware and keep a firm peddle and stiff parking brake.