I flush my BF every 2 years in my spyder. What I have are these nifty bleeder vales called speed bleeders about 7 bucks a valve (they work on the clutch too)
Have not idea what size you would need but call these guys and they will tell you.
it's a one way valve that when you take you foot off the pedal you do not let air in. It is still better to have an extra set of hands (or an extra foot LOL).
Always start at the wheel farthest away from the master cylinder and then work to the next closest and so on. Thus you are starting with the rear brakes and moving to the front.
I have not done this yet.
Thanks for the lead to the speed bleeders.
Anybody knows what speed bleeder thread size I need for the burb?
I just bleed my brakes yesterday
AS Pikey has been saying the trick is to make sure you keep putting fluid into the MC and not let it go dry. I second the recomendation of PB blaster on the valves and I did not get the speed bleeders I recommended above as I did not have time to pick them up AND given the corosion on the calipers I do not think i could have installed them anyway.
I use two floor jacks (one on each side of the car) to lift first the front and then the rear of the car. support the car on 3 ton jack stands (3 each side on the frame rail)
-I take a turkey baster and remove 2/3 of the MC fluid replace with fresh
- start at the wheel farthest away from the MC and move to the next farthest passenger rear, driver rear, passenger front, driver front.
- I had 3qt of Dot 3 on hand (only used two ) flushed an entire QT
- this is a two man job one person to operate the bleeder valve and catch the fluid and another to pump the pedal and add fluid to the MC
- when you are finished bleeding the respective line, the pumper needs to hold his or her foot to the floor and keep it there until the person on the valve has it closed. Check the seal on the valve by pumping the bake after this and the valve worker can check for leaks
takes about 30 minutes once the car is up
I've always tried to do my fluid every two or three years. The fluid is a magnet for moisture, and newer fluid beats older fluid any day of the week. Even if the older fluid is still working OK, it's such a cheap and easy maintenance job...
Now the 2001 Suburban has 185k miles and the brake pedal started getting spongy. Sometimes it nearly goes to the floor.
I bled the system using a power bleeder and still spongy. Well, the truth is the brakes on this model Suburban has not been great since 8k miles new. It has always been on the mushy side compared to the 2011 Silverado.
I plan on replacing the master cylinder.
I have two choices.
1. AC Delco 18M1159, with 34mm bore for Vacuum boost. (Stock)
2. Dorman M630035, with 37mm bore. for Hydroboost
Which one will be a better choice for better pedal feel?
I don't know if the hydro boost unit will work. I don't know that the rod is the proper length, if it did itr may be harder to depress the pedal with a vacuum booster rather than the hydro booster. I have a hydro boost in my 05, the pedal was still spongy. . Last friday night I switched all of the soft brake lines to braided stainless steel. It took about an inch of travel out of my pedal. I have to be careful, between the lines and the power stop pads and rotors it stops much faster and with less effort. since friday I have hit the pedal "normally" 4 times and if I did not have a seatbelt on it would have put me thru the windshield. I bleed my brakes after changing the lines with a motive power bleeder I just purchased. The best $60 I have spent in a long long time. (oh, if you do look at replacement lines, make sure it is a 5 line kit, or 6 lines if it has traction control.
Originally Posted by bazar01
on another note. If you change the master you may have to take it to a shop or dealer to have it bled. From what I understand, with the tech 2 they have the ability to cycle the abs valves to get all of the air out of the system. I have heard of guys bleeding them. driving it to a dirt road and slamming the brakes to get the abs valves to cycle. then bleeding them again. This is why I purchased the power bleeder. I was told by a few gm techs that if I pressurize the system to 15 psi it will force open the abs valves. I don't know if this is true or not. But it worked great for me.
Thank you for the reply.
I called Summit and talked to the tech support guy and here is what he said
-The Dorman M630035 master cylinder will not work on Vac assist $85
-The correct Dorman master cylinder is MC630031 for Vac assist. $66
Regarding cycling the ABS valves, I am not convinced that the 15 psi will activate the ABS.
With a master cylinder bore of 34mm (Area of 1.4 sqinches), that only needs a foot pressure of 21 pounds.
I think you need more than 21 pounds to slam on the brake pedal and lock up the wheel and activate the ABS.
I think I might try the dirt road and slamming on the brakes then bleed after I replace the master cylinder.
yea, I don't know either. All I know is that it worked well for my situation.
Originally Posted by bazar01
Ok I went out in the country and found a dirt road. Drove it at 50mph and slammed on the brakes. ABS worked and I felt the brake pedal pulsate and the traction control display showed "Low Traction" message ON. Did it 3 or 4 times then went home. The brake pedal never went to the floor when I slammed on the brakes which is a good thing even though the pedal is a little soft. But when the ABs worked, the pedal felt like it was going down further every time it pulsates.
It was dark already so I was not able to bleed the brakes. I will bleed it tomorrow and see if the pedal feel gets a little stiffer.
I figure I will update this thread.
I bled it again after cycling the ABS by slamming on the brakes while going 50 mph on a dirt road last week.
The brake pedal improved very little but it stops better now. The pedal is still soft compared to the 2011 Silverado but at least I did not have to replace the master cylinder.
Drove it to Atlanta and back about 400 miles this past weekend and it stops way better.