DIY Brake Bleed and brake booster test

roro 93

New Member
i will now tell you how to do a simple brake bleed on your car to remove the air from the system
resource: ED MAY automotive
before commencing the bleed, check the master cylinder reserviour and top up if necessary. The fluid must be maintained at a reasonable level during bleeding to ensure no air is drawn into the master cylinder.
*NOTE: you may need to top up the reserviour several times during bleeding*

Today i am explaining manual bleeding

1) attach a plastic tube or length of hose no longer then 40cm to the bleeder nipple on either the wheel cylinder or brake caliper, ensure it is a good fit over the nipple, the other end of the tube or hose should be placed into a bottle either a coke bottle or whatever you have, and it should be partially full, water will do or clean brake fluid (this ensure no air will be drawn back through the nipple)

2) unscrew the nipple 1/2(half) to 3/4( three quarters) of a turn to allow fluid to flow through the nipple

***MAJOR NOTE: if it is an old master cylinder, only pump the brake pedal as far as you would when normally braking, or damage to the seal and cups could result from travelling to a section the master cylinder hasn't seen for 10 or so years, then the pedal will sink to the floor and you will be up for a lot more then a bottle of brake fluid***

3) have an assistant slowly pump the brake pedal several times ensuring not to bring the pedal back up suddenly, this will pump the fluid through the system into the bottle, after a few pumps check the reserviour and remember how much the level drops for each set of pumps eg. 5 pumps at a time, if the hose is submerged the hose will bubble if any air is coming out, if no bubbles then there is no air in that particular section

4) when bubbles cease to appear and only fluid is being discharged from the hose you can then tighten (nip up) the bleeder nipple. Now before proceeding to the next wheel cylinder or brake caliper, check the reserviour fluid level and top up accordingly

** if unsure about the tubes sealing ability or the assistants workmanship, for added confidence you could nip up the bleeder nipple with each return stroke of the brake pedal, (when the brake pedal is released to its normal position)**

5) repeat the above steps for each caliper/cylinder

finish now that all 4 calipers/cylinders have been bled, pump the brake pedal a few times, it should feel firm and not squishy or spongy, if the pedal is squishy or spongy more bleeding may be required, if normal bleeding does not fix it then you may need to bleed the master cylinder. Now start the vehicle and feel the brake pedal it should feel somewhat firm but you shouldn't have to put much effort into it

Brake Booster Test
Now a simple test

1) ensure car is not running and key is off
2) pump brake pedal until nice and firm
3) hold pedal down as if you were braking hard (not epicly/stupidly hard)
4) start engine with foot still firm on brake pedal
5) if the vacuum booster is working correctly then the pedal should drop about 2-3 cm whilst applying pressure still, if not then you will have a hard time braking and should consider replacing the booster
 

Jazza

Active Member
Also to add in, start from the wheel furthest away from the master cylinder and work your way closer to it. So since CE's have their cylinder in the right side of the engine bay you'd start off with the left rear wheel, right rear, left front, then right front to bleed. Just for those that don't know :p
 

roro 93

New Member
Jazza2442 said:
Also to add in, start from the wheel furthest away from the master cylinder and work your way closer to it. So since CE's have their cylinder in the right side of the engine bay you'd start off with the left rear wheel, right rear, left front, then right front to bleed. Just for those that don't know :p
haha good work jazza, forgot to mention that part haha
 

donki

Administrator
Forum Administrator
Just to add to this, the actual correct way to bleed a CE lancer is diagonally. However, im unsure at which point to start off at. It IS listed in the Gregorys Manual.
 

shoom

New Member
You just strart from the Passenger side (left for us Aussies) rear wheel and then front Driver's side, rear Driver's and then front Passenger.

Get yourself one of those Toledo (or similar) one-man bleeding kits from Supercheap etc. I had a problem with a air pocket somewhere that I just couldn't find, and was tearing my hair out after trying 3 times unsuccessfully to bleed my brakes after replacing all the pads and shoes. Was going to take it to a shop and have them do it, which goes completely against my autodidactic tendancies and fear of shops. Bit the bullet and decided to see if these were any good in a last ditch attempt and It did the trick, now my pedal is as stiff as a Rock!! You go thru a little bit more fluid bleeding them, but it's worth it. You loosen the bleeder valve about 2/3 to 3/4 of a turn and get in the car and pump the pedal slowly up and down about 4 times, then you go back to the wheel and see if there are any bubbles in the line, no bubbles, good to go, tighten the nipple, remove the hose, wheel back on and next wheel in sequence. (The container included in the kit has a magnet that attaches to it which has to be mounted above the bleeder nipple) Did the trick for me.
 

Dutch

Active Member
If you only crack the front 2 lines (ie to upgrade the front calipers), does that mean only the front will have to be bled?

My thinking is the rear lines won't be affected so they shouldn't need to be bled.
 

donki

Administrator
Forum Administrator
If you only crack the front 2 lines (ie to upgrade the front calipers), does that mean only the front will have to be bled?

My thinking is the rear lines won't be affected so they shouldn't need to be bled.

Nah, the front right and rear left are linked, so touching the fronts mean the rears need to be done as well.
 

shoom

New Member
The best advice I can give is to loop the hose around a suspension arm or similar so it's higher than the bleed point, it's not strictly necessary to have the container higher. Just is more convenient with this setup.
 

Dutch

Active Member
Nah, the front right and rear left are linked, so touching the fronts mean the rears need to be done as well.

Arse, that's like twice as much work lol.

Will be recruiting the missus for brake pedal depressing duty, on the premise it was only gonna take 20ish minutes, now I might be lying... :p
 

frosty7

Active Member
You shouldn't need to bleed the rears if the master cylinder reservoir didn't run dry. Try only bleeding the fronts and see if you have a good pedal. If the reservoir drew in air all four will need a bleed.
 

shoom

New Member
Just remember that if the fluid level in the master cylinder drops below the bottom, you'll have to bench bleed the master in a vice or at the very least bleed it in the car with an assistant (messy) The best thing to do is to buy 2 x M10 nipples off fleabay that fit the master and attach elevated tubing to either as it's alot cleaner than the traditional method of pushing your fingers down over the line outputs as fluid tends to squirt out as you pump the piston in. They can be finnicky, sometimes even just getting them lower than the minimum mark can introduce air into them. All you DIYers out there have fun! , if you ain't dirty you ain't putting your back into it and seasons greetings all round.
 
Top