The Stovebolt Site Forums The Shop Area The HiPo Shop How do you bleed under floor brakes?

The brakes on my street rod continue to give me grief. I need to find the best way to bleed them once and for all.
The facts:
Under floor m/c with two stage (pancake) 7" booster.
Thru floor pedal
Corvette dual m/c (two large reservoirs), 1-1/8 bore
Corvette 11" disc front, '86 Camaro rear drums
2 pound residual valve front, 10 pound rear.

I lost the front brakes at the NSRA south show over last weekend from a failed rubber front left hose. Replaced the hose and attempting to bleed the front. I would like to be sure no air is left in the lines. This is always a problem as the rubber lines and maybe other parts are above the m/c.
I have a hand vacuum pump, an electric vacuum pump, self bleeders and normal bleed valves.
How would you do it?
Thanks

If you have air in them you should be able to "pump up the pedal" and then let it sit for a few minutes. The press the brake pedal down and see if it goes down lower than where you pumped it up to. If that happens you surely have air in them.

Since you only messed with the front I'd think those are the only ones needing to be bled.....and in most cases I'd say only the one wheel where you replaced the line.
Maybe someone who has had the same problem will chip in here.

First always make sure the master cyl is full while bleeding.
Start with the farthest away from the MC wheel cyl and if using a vaccum you need the special little jar deal so you don't suck brake fluid into the vac pump. Hook up that bleed setup and loosen the bleed valve at the wheel cyl, till the little jar fills about 3/4 full, then close the bleed valve and empty the jar. Do that about 2 to 3 times, then move on to the next farthest wheel cyl, repeat. The closest one is last. That should do it. The thing you want is no bubbles comming into the little bleeder jar.

I use a Motive brake bleeder - the best way to bleed any brake. I modified the floor pan so I could get to everything.

http://img.photobucket.com/albums/v228/Avette4me/My%2058/Brakes/Initialmockup.jpg

http://img.photobucket.com/albums/v228/Avette4me/My%2058/Brakes/HoleforMasterCyl.jpg

http://img.photobucket.com/albums/v228/Avette4me/My%2058/Brakes/CoverforMaster-mockup.jpg

I guess I need to distill my question some. When one goes into their FAPS and gets a master cylinder there no instructions as to which reservoir is for front and rear (at least not that I have seen). I looked at the very good "MPB" web site for some insight. They show a number of master cylinder hook ups. You guess it, some pics show the front brakes going to the reservoir closest to the booster. Other pics show the reverse. When I bench bleed this m/c I closely watched which reservoir moved brake fluid first.
Another question is, which system is suppose to start braking first, front or rear?
Please remember, this is a street rod. You don't usually go into the auto parts store and ask for the parts by make and model then drop it in.
Thanks

You could trace your lines to find which is front and which is back on your "street rod" if you only want to bleed one side.

If it were me, and the brakes were working well before things went south, I'd assume they were routed correctly and bleed all of them.

x2 on bleeding them all.....we used a vacuum bleeder to do mine...it was a new install on the whole system...lots of leaks..but eventually got it done......whid

Hopefully hopeing to not sound like a smart a** but please retread my questions. I am very familiar with my brake lines as I put them in. Thanks

I would bleed the entire circuit


If you can’t access the MC, I would clean that up. You have to fill it eventually.


Motive pressure bleeder.

But that’s just me…

Agreed on both counts. It was also mentioned to bleed starting with the cylinder furthest away from the MC. What you would want to do is start with the longest line, which, depending on how the lines are routed, could be either the RR or LR. I would suggest checking the routing of the lines to determine which one is the longest line.

i have a problem bleeding brake by myself. my 40 is a pain. i got a set of these. http://www.speedbleeder.com/
i got mine for napa. i did the complete truck including the hydravac in less then a half hour. theyre sort of pricey but its less than the cost of frustration.

This is what I saw at homemadetools.net website

http://www.homemadetools.net/power-bleeder-2?utm_expid=57824293-7&utm_referrer=http%3A%2F%2Fwww.homemadetools.net%2Ftag%2Fbrake-bleeding

http://forums.corvetteforum.com/c3-...wer-bleeder-for-14-a.html#post1578587678

Update....
Tried using both the hand vacuum pump and the electric vacuum pump with speed bleeders. I could not get a good seal where the vacuum hose fits over the bleeder nipple. It kept leaking air and was impossible to tell if air bubbles were from the the brake line or air leak. I was using clear Tygon tubing.
Had more luck with the self bleeders and pumping the brake pedal.
I like TimyJaime power bleeder. The problem I would have with it are the clamps. It's very cramped around my m/c with tubing, residual valves, and frame members.

Yes i agree about the space issue. Mine too is under the cab however my cab is off so mine is wide open right now but i am planning to install a mini door or access panel for future service. I did not think of other peoples situations. Well good luck with it.

It's done. What worked best for me.... using the brake pedal with the self bleeders. As stated above, in using the vacuum pumps I couldn't tell where the air bubbles were coming from.
If someone has a good way to get a rubber hose on the bleeder nipple I would be interested in reading about it. Thanks

Don't buy the cheap vinyl tubing, get the softer stuff, I know its used for fish tank air pumps and I have had good luck with it staying on the bleeders.

.... I just tried what I had laying in the shop. Be it vacuum hose or windshield washer hose ect...

I used the speed bleeders myself and love them.

the speed bleeder eliminates the use of any other bleeding type device. its the brake pedal and master cylinder that does all the work. as for a hose over the end of a bleeder to catch fluid and not leak air the tighter the better method is best. with a speed bleeder you'll get no air bubbles from the bleeder when your not pressing the brake pedal. you'll get no air bubbles going back into the bleeder unless of coarse the check valve in the bleeder is faulty or was rendered useless due to junk in the fluid from old dirty nasty brake lines that havent been replaced .



ahh the price of modifications