I am ready to rebuild all four calipers on my 69 and I would like to know if I should do one and then bleed it or can I do all four and bleed them all. I'm also replacing the master cylinder and I want to drain all the fluid. I'm also replacing all the rubber brake hoses. What do you think? And if I do remove all at once, In what order should I bleed the calipers? R/R, L/R,R/F, L/F.
Thanks
Sly

 

OK so you are going to have all NEW fluid in the sytem and all new hydraulics. Good stuff ... don't buy the wrong fluid.

First: BENCH BLEED THE MASTER CYLINDER!! If you don't know how or have not heard of this before, LEARN IT!!

After a BLED master has been installed and the calipers too, bleed the right OUTER rear bleeder. Then the LEFT OUTER rear bleeder.

then to to both inner rear bleeders. Next comes the right front and the left front (only one each)

Pump the pedle and pump then pump some more.

Repeat procedure (calipers only - leave master cylinder alone) from top to bottom. and it will be good as gold.

 

According to the manual I have, the pattern is:
LRI, LRO, RRI, RRO, LF, RF

Bring plenty of brake fluid and some patience ...it takes a while to get all the air out. If you aren't careful, you can run the master cylinder dry, and then it's a do-over!

Bench bleeding the master cylinder is a good idea, and worth the time.

Brian.

 

IMO, you have to do a bench bleed if you replace the master cylinder,

What is the general opinion here about gravity bleeding? It makes a mess but seems to work out most of the air if you're patient.

 

i would take the whole system apart and rebuild all the calipers. then i would use compressed air to clean the lines and switch to DOT 5 fluid. bench bleed the m/c and reassemble the system.

there are springs behind each piston. if you do a search here there are a couple of threads that talk about leaving out those springs. i just did the same thing you are doing and i left the springs out of all the calipers. the car seems to stop...

 

Gravity bleeding works, but takes......all....day.....days???....I use the Motive Products Pressure Bleeder; excellent results in the time it takes to run from caliper to caliper.

 

the only way i can succesfully bleed them is using the gravity method,
just replace my flexi hoses last week and it only took about 5 mins each wheel to bleed them, the pedal is great,
natt

 

what's the difference between gravity bleeding and pressure bleeding ? isn't it the same, only that when pressurizing the system you're accelerating the process.... ??? right ????

Here's my pressure bleeding setup:

 

yeahhhh... don't forget the master cylindar..... i did.... and have to do it over... but getting all new brakes... DEFINATLEY worth it... turst me! goodluck!

 

I rebuilt all 4 calipers Master cylinder was off and completly drained. I didn't bother to bench bleed the master cylinder. I am not convinced it needs to be done in this situation. If the master cylinder is the only thing being changed and you don't want to bleed the whole system, then a bench bleed is necessary.

Put all components back on the car. Fill up the master cylinder. Pump the brakes until no air bubbles are seen coming up in the master cylinder. This is a two person job by the way. The goal of bleeding brakes is to remove any air in the system. Again I am not convinced there is a special order, just as long as the air is removed. Since most manuals list the rears first, I start there. I have a cheap bleeder system from Harbor Freight, $4.99. It a little plastic bottle that can be held on the car with its magnet. It also has about a 12" clear hose that attaches to the bleeder with a funnel type connector. The thin end of the funnel slips into the bleeder. Break free the bleeder, insert the funnel, push down the brake pedal, open the bleeder, close the bleeder, and let the brake pedal return. It will take numerous times before you see and fluid flowing through the clear hose. On the rears, I would start doing the bleeder on the same caliper before finishing the first bleeder. Once fluid is coming out of this bleeder (may only take 2 pumps of the pedal), it will be mainly fluid. Hit the caliper several times with a rubber malet or a block of wood and a hammer. This will try to dislodge the bubbles that may be in the caliper. Resume bleeding until you see the fluid is all fluid without any tiny air bubbles. Go back to the first bleeder and bleed until air-bubble free. Do the other calipers in a similiar fashion. Keep an eye on the master cylinder and keep it full.

The great thing about the clear hose is that I was surprised how many times the bleeder had to be opened until a stream of brake fluid without bubbles was noticed. Had I just opend the bleeders until a shot of fluid came out, there would have still been air inside the caliper. Most if not all the brake fluid is captured in the plastic bottle instead of trying to wipe it up with a shop rag.

 

Yeah,..same process, just pushing it through faster. Seems to be the best and most successful way to bleed.