brake bleeding tools

[underkut]

I am close to require bleeding the brakes on a project , brakes have been completely rebuilt and I don't fancy having someone in the garage for an hour or so whinging their leg is hurting.
I have used an old eezi bleed system before and found it ok as long as the cap has a very good seal.
Has anyone used the eezi bleed TE754 vacuum system. This looks far more professional but still cheap.
I do have a brake valve at the rear and I know these can cause problems.
Any advise would be appreciated

[1071 S]

Depending on your master cylinder sealing the cap for an ezibleed can be a problem... However, I have both systems (ezibleed/vacuum) and find there's a place for both.

The (my) vacuum pump only has a small reservoir so takes a lot of work to suck the fluid through if the entire system is dry. I would use the ezibleed to fill up the system. Then, after allowing things to settle down, I would finish off the slaves with the vacuum pump.

One trick with the ezibleed is to NOT use too much pressure. 5-10psi more than enough. Such pressures won't affect (initiate) the rear brake limiter.

Cheers, Ian

[Spider]

Be aware that using a vacuum source to bleed brake systems can (and often will) also draw in air as the slave cylinder seals are not designed to seal with a negaive pressure, only a neutral or positive one.

I've been using the Ezi-bleed for a few years now, only I don't fill the bottle on it, only because it will atract moisture and also getting the cap off at the end of the job mess free can be a challange. I also use a dry air source to reduce the moisture introduced to the system. As 1071 S has said, a low pressure is best.

[goff]

How did the production line or off the line bleed the brakes , just curious
Goff

[Spider]

How did the production line or off the line bleed the brakes , just curious
Goff

Dunno about BMC / Leyland, but I know Ford Pressure Bleed, using an Industrial version of the Gunson's Unit.

[ivor badger 2]

How did the production line or off the line bleed the brakes , just curious
Goff

A vacuum system operated from a pit at the end of the production line.

[underkut]

If bmc did use a vacuum system then i guess they did not experiance many problems with the cylinders letting air by backwards.
Maybe the experiance that Spider has found could be due to worn seals but i can picture his concerns?
I have new seals all round so hopefully i will be ok but as they say for warned is for armed so if i do have an issue with the vacuum then i will know where to look .
many thanks for your guidance. I shall update next week with my findings.

[dklawson]

For the one-man bleeding I often have to do, I have a bleed hose with a low pressure check valve inline. With the bleed hose connected and the nipple cracked open about 1/2 turn I slowly pump the pedal to move the fluid through while monitoring the reservoir level.

On completely dry/empty systems I have had to resort to cracking each piping connection open (to allow a little fluid out) moving from the master cylinder down to each wheel cylinder. Once you get some fluid out of each joint and re-tighten almost any method of bleeding will finish the job for you.

[ivor badger 2]

Easi bleeds were really handy for bleeding cars with replaced pipes. If the m/c seal didn't seal on the first press, you had to replace the worn seal to get the car to bleed. Using an easi bleed allowed you to get a pressure seal on the m/c and the system would normally work with a worn seal. As you have new seals, it should be no problem bleeding the system either way.

[Tim]

I've used a variety of techniques for one-man-brake-bleeding and I like the older pressurised Eezi-bleed. It can be a bit messy but does seem to speed things up.

If you're using a vacuum system something to watch out for is air leaking in around the thread of the bleed nipple. It can make it looks like air is coming out of the wheel cylinder. You could probably grease the threads with rubber grease and only crack them open a little way.

Tim

[andy1071]

Most factories use a vac/fill, that is, they apply a vacuum to the complete system, and then pressure fill (so they don't have to bleed the brakes, in the normal way, so saving time).
But I'm not sure when this was introduced.

But, the wheel cylinder seals, and the secondary seal in the master cylinder were always designed to withstand a complete vacuum.
Having said that, it is known that the vertical master cylinder does have a tendency to 'gulp' air passed the secondary seal on its return stroke....

I use an Eezi-bleed, and as has been mentioned, the lower the pressure the better. I try to use only 5psi.
And yes, it does tend to be a bit messy.

But remember you can wash away brake fluid from surfaces with lots of water.
Don't think this works for silicone fluid though.... (but of course, we don't use that stuff, do we?)

[underkut]

Well i did get the vacuum pump and my findingd are
Its rubbish for a 1300 and therfore for a mini.
The rear nipples are to small .
It did work very well on the clutch though.
Next time i will go back to the easibleed run at very low pressure.
Did get therein the end though and quite easily so the vacuum must have started sucking it through.

[Spider]

Here's what a manufacturer / supplier has to say about bleeding brakes;-

"Pressure bleeding

This method requires the use of a pressure bleeding unit, such as the Partswise® Bleedpro system. The unit pressurizes the fluid in the reservoir, and the bleeders are opened in a sequence until no air is left in the system. There are 2 main advantages with pressure bleeding. First and foremost, it is fast, and one person can do the job. Secondly, pressure bleeding has an advantage when used on older vehicles that have had little maintenance. The master cylinder does not have to be stroked to push fluid through the system. On an older car there is sure to be corrosion and dirt inside the master cylinder. Stroking the pedal to the floor moves the piston deep into the master cylinder where it would otherwise never travel. The seals may pick up dirt and be damaged. Pressure bleeding avoids this.

Manual bleeding

This method requires the use of the brake pedal and master cylinder as a pump to expel air and brake fluid from the system. This method is usually a 2 man operation. Starting at the wheel that is determined by the proper bleeding sequence for the vehicle being worked on (you will probably need a manual or database for this,) one person opens (during the pedal operation) and closes (prior to pedal release) the bleeder screws and observes the air bubbles while the assistant pumps the pedal slowly. Usually the fluid is bled through a piece of clear plastic hose into a jar with fluid at the bottom. Keeping one end of the hose inserted in the fluid will prevent air getting into the system when the bleeder is open. To ensure no air can be sucked back into the system, the bleeder screw must be closed at the end of each stroke, before the pedal is released.

Vacuum bleeding

Vacuum bleeding can be done by one person. Vacuum bleeders usually utilize shop air pressure and a venture principle to suck fluid from the bleeder. Vacuum bleeding does have drawbacks in that it can allow air to be drawn in past the seals, thus creating more problems."

http://www.nbsbrakesupplies.com.au/tech ... stems.html

PBR, who supplied new Brake Parts for our local Mini Production also only recommend Pressure Bleeding.