Brakes - Bleeding a dry system?

Soldato
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18 Oct 2002
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Location
Wellington, NZ
Hi, right i'm on to the last step then I can drive the car. I swapped the master cylinders around when I did the swap as mine looked bad plus it was getting pedal creep.

I topped it up yesterday and tried to bleed it but all that happened was a few drops then nothing, the fluid wasn't even going down. This was the same with all the brakes.

Is there a special procedure to bleeding a dry system?
 
Here is the complete directions on brake bleeding as per how I learned it over 20 years ago. There are ways to do it solo, but I feel this way is 100%.

1. Get a partner to sit in the car.
2. If you can reach without taking the wheels off, all the better. Depending on the car, it might mean you have to park with the passenger's tyres on a kerb so you can get under the rear end.
3. Get the proper size socket. DO NOT use an open end wrench. You will strip the bleeder nipple.
4. Start at the passenger's rear wheel, then the driver's rear, passenger's front, then the driver's front.
5. Crack the nipple loose, then tighten it back down.
6. Set up a communications system with your partner. I generally use "pump" and "release". You'll be saying them a lot, so use something short.
7. Have parnter pump the brake pedal about 4 or five times then on the last one hold the pedal in the down position.
8. Open the nipple to release the pressure.
9. When parnter says the pedal's on the floor, close the nipple.
10. Have partner release pedal.
11. Check fluid level in master cylinder to ensure you're not sucking air in.
12. Repeat steps 7 through 11 until clear fluid comes out the nipple. Move to the next wheel.
13. Top up master cylinder and you're done.

If you started with a dry master cylinder, you might have to take the lines off it and pump it a few times to prime it.
 
Only thing I'd add to that is when pumping the pedal to not let it go quite all the way to the floor as doing so can damage the seals in the master cylinder.
 
Hrm, you could be right, sounds quite reasonable, but I've never had a problem before.

Just as a precaution maybe put a block of some sort under the pedal so it doesn't drop all the way down.
 
Guess it depends on the exact design of the MC. It's usually mentioned as something to be wary of whenever anyone describes the process on an MR2 so it could be specific to those or a more general thing.
 
are there kits that suck the fluid out or put pressure from the top as that would be useful as I'm on my own today :(
 
I had one that uses the pressure in the spare tyre to pressurise the top of the the reservoir but never got to see if it was any good as it didn't have the right fitting for my car.
 
AmDaMan said:
are there kits that suck the fluid out or put pressure from the top as that would be useful as I'm on my own today :(

Yeh there are kits that do that and are pretty good and are easy to use. You just fill up your res and the bottle that comes with the kit with brake fluid, attach the right adaptor to the res and the connect the other end to either a spare tyre or one of your front ones. After that its just a matter of starting from the rear corner furthest away from the MS and bleeding that brake first by slackning the bleed nipple, then moving to the front wheel on the other side - so your working diagonal opposites, then the same for the other two. I replaced the master cylinder on my old saxo and use on of those kits to bleed the whole system and it was really simple - just keep any eye on the fluid levels in the bottle and res, if they get down then you'll be filling the lines with air!!! Remember the system wont be 'dry' as there will still be all the old fluid in the lines, so when bleeding give it enough time for all of that to come through first and them you'll start gettting the air coming out.
 
That Gunsons Ezebleed system you can get from places like Halfords has worked well for me in the past. Sure is a lot more effective than getting someone to pump the pedal.
The only bad part is you tend to get through quite a bit of DOT4 fluid, but hey it's cheap from motorfactors :)
 
kaiowas said:
Guess it depends on the exact design of the MC. It's usually mentioned as something to be wary of whenever anyone describes the process on an MR2 so it could be specific to those or a more general thing.

This advice comes from old master cylinders that can either have a wear ridge or surface rust formed past the end of the normal stroke of the piston. My boss recently fell foul of this when bleeding the brakes on his 911, he pushed the pedal down to the floor and it stayed there due to the piston jamming at the end of the master cylinder.

There should be no problem with a reasonably new master cylinder.
 
cheers folks, just got one from the factors, its working very well indeed.

Made the mistake of leaving it on and doing something else while the nipple was close and it ****** a half full pot of fluid on the floor ha ha,.
 
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