Should the reservoir cap be on or off when bleeding the brakes?


I have a little air in the system from when I did the brake job that I haven't been able to get out. I tried the power bleeder, and the old school method. I bought some speed bleeders Speed Bleeder Bleeding Brakes Bleeding Motorcycle Brakes Automotive Bleeder Screw Brake Bleeder for my motorcycle that worked great so I decided to buy some for the car. Question: is it better to bleed it with the car running or off? Seems to me with the car running, all systems would be involved and get a better bleed, but this is where one of the experts can chime in.


Thanks

 

No need to have the car running,or you'll have power assisted bleeding.LOL It helps to have some feel on the pedal, so engine off.
Change all the oil while you are at it with fresh just opened oil, a different color helps.
I have not tried the speed bleeders, I used my buddy on the pedal. I tried a vacuum bleeder but my buddy offered to help.

 

I tried the buddy system, that's what I meant by old school but I still must have some air because when I first press it, it sinks about an inch before engaging. The second press it is instant.


How about the reservoir cap? Does it matter on or off?

 

The cap is normally OFF, because you need to replace the missing fluid as you bleed the brakes.
NEVER LET THE RESERVOIR GO DRY !!!
If you do, then you gotta start all over again on all 4 wheels.

 

I replaced my bleeder screws with speed bleeders and no regrets. Very simple one man operation to bleed my brakes.

 

That is the way they are, if you had air it would always be spongy.
I had what I thought was a spongy pedal, I was told that it was OK. I even tried a new master cylinder, and it was still the same.
I leave the cap on loose. You do not want the oil splashing over the side.

 

I've never had favorable results with the one man vacuum system. If the technique is faulty you'll fail. The friend pushing the pedal works well and it's the system I used for years. Now I just gravity bleed one wheel at a time, washing the wheel and wheel well as it drips. Perfect every time. I don't know if it makes a difference or not if the cap is on or off but I always bleed my brakes with it off. Never with the car running, even though I've seen it done that way before.

Les

 

I was afraid of that. I did these brakes several months ago and it has not changed. Never goes down further while holding pressure. I just don't like the lag on the first press. When I 'm driving aggressive I want instant brake! I should note I used the power bleeder probably 5 times and the buddy system once. Never really got any more air out of it after the first or second time...just hoping another method might help but it sounds like it might just be the way our cars are.

 

I've never tried the gravity bleeding but a lot of people like it. How long do you let it run? Until no more bubbles and then a few more minutes?

 

I can tell you for a fact that on "some" Chrysler/Dodge products you must have the car running to properly bleed the system. Maybe just key on, I am not sure because I let them run. When these particular cars are not running, the ABS allows air to be trapped and you will not get a good pedal until you bleed the system with the ABS system functional.


I know that the Crossfire is technically not a Chrysler.

I have a Mity Vac vacuum bleeder and have used it on dozens of cars with no trouble.



James

 

It has been two years since I did mine and I think I read that this system does not have air traps in the ABS pump. It is something to do with the pistons and valve set up. I could be mistaken though. I should check.
But I guess it would not hurt to have the engine running.

 

Yeah, mity vac works. BUT, you need to wrap the bleeder screw threads with some teflon tape, or air will get sucked in around the threads. Be sure not to wrap over the hole.

 

Old school works well on these cars as I have owned 4 and all were changed out and bled with the 2 people method and starting with the farthest brake and working your way back to the closest to the reservoir .....never had an issue unless 1 of the bleeder screws is leaking or a brake line is bad.....

 

I gravity bleed them too and haven't had any problems. It's definitely the easiest way. With some carefully placed Aluminum foil and a pan there isn't much to clean up either. I leave the cap off too.

 

Holly crap, Chuck Norris drives a crossfire!

 

Ok guys. So those who have gravity bled how is your pedal? Does it go down 1/2 to an inch before engaging?

I also liked the speed bleeders because the thread was much tighter. I think that was the problem on my motorcycle. I ponied up for the stainless steel ones. Not pimping them and at $15 each not cheap but well made.

When you gravity bleed, how much do you let run out? A reservoir worth on each caliper?

 

I have not had to bleed the brakes on my Crossfire yet, but with my other cars, helping my son's and friends with their cars, I guess I've easily done over 100 brake jobs.

I've never had a need to have a car running while bleeding the brakes, and have no reason to recommend doing that. On one car I had fluid come out of the brake reservoir while pumping the peddle when I forgot to put the cap on, so I always try to remember to do that. I don't think that is required for every car, but I do it consistently to avoid a problem. Brake fluid damages car paint! One time I didn't check the reservoir fluid level soon enough while bleeding the system, and the reservoir emptied which introduced air into the system, so I had to start over on all 4 wheels.

Never tried the automatic bleeder screws. I bought an expensive Motive products brake bleeder which is a pressure system that pushes fluid down from the reservoir. Mixed results from that. It needs many different adapter caps and the universal cap sometimes leaks. Another tool, the hand vacuum pump does not always seem to have enough suction on some systems. The old fashioned way to have someone pump the peddle while I tighten and loosen the bleeder screw seems to work the best.

 

When I gravity bleed I watch how much fluid is in the jar. I like to replace all the fluid in the respective caliper plus a little. Before I start, I fill the reservoir to the brim in case I have a brain fart. I'd say 10 minutes per caliper more or less. The pedal …… that soft pedal. With gravity bleeding I've avoided it. With the 2 person method I commit sacrilege and pump the pedal before the last few strokes.

Les

 

Not a reservoirs worth, that gets expensive. It is nice when you have two colors, let it drain until the color you put in the EMPTIED reservoir comes out the nipple. With the small lines the two colors do not get to mix much so the change is soon evident. Otherwise drain until you get no bubbles. That is usually just when the new color comes through.
The pedal always goes down a bit before the brakes engage. There is or was a reason for this, the play is there because there is a gap between the booster push rod and the master cylinder rod. This is to allow expansion of the fluid not to push against something solid. If it did the brakes would apply because the expanded oil would operate the wheel brake cylinders. That's how I remember it anyway, check it out.

 

This is what I have been looking for. Thank you!