hi guys im just starting to learn general mechanics and iv just fitted new suspension and brakes but I wasn't very confident in bleeding them up so got a local garage to come out and bleed them now they feel worse than when I attempted
Get them to come out again then and complain. What brakes did you fit. Are you sure you fitted them correctly
I have im waiting again, should they all bled all 4 brakes or just just front as the caliper was disconnected
If you had a caliper disconnectd you want to get all four bled
What method did they use to bleed ?
they just made me pump the brake then let off while he did the nipple up
If you drained the brake fluid. All four nees doing. If you locked the line off you only need to bleed one.
You need to do all 4. It'll probably take at least half a bottle of fluid to bleed properly. You need to do then in the right order too. I believe its NSR OSR OSF NSF
As Sam said ^ bleed all brakes to be safe from closest caliper to the furthest from the mbc.
There is a risk of damaging the master cylinder piston seal when you bleed brakes on old cars with that technique, rust inside the cylinder bore can scratch the seal.
During normal use you never manage to push the pedal all the way down but when bleeding you do.
Is your pedal spongy or does it sink slowly to the floor? Or do the brakes just not bite?
It's not rust (or shouldn't be unless there's water been in there), it's the fact that there'll be a wear lip that the seal goes over after years of use.
pedal just feels soft and you have to push pedal to floor for it to brake
If you've fitted brand new pads/discs they'll take a few miles to bed in.
it wont got tho floor tho, they need bleeding again
brake fluid absorbs water from the atmosphere ( does modern dot 5 stuff do that as well???? ) etc........
gravity ( with m/c cap off ) could be used for a very basic bleed, when fluid and no air emerges from the nipple then its time to bleed properly......
get an assistant that will do exactly as you say as you will be the one in "command" at the nipple.
follow the procedure for which nipple to bleed first etc...........
with all nipples showing air free fluid flow via gravity method, and with all nipples closed, start at the nipple furthest away from the m/c.......
get the assistant to "pump up" the brakes with say five firm presses of the pedal ( the "pump up command" ) in quick succession with them taking the foot off the pedal each time so the system can pressurize and fill etc........then press the pedal ( the down command ) down and keep pressing ( not over the top and trying to burst a pipe etc ) which is the "down command"......then the assistant says "down".........so you know what they are doing!!......at this point open the nipple gently and watch the fluid emerge from the nipple, go thru a clear plastic pipe and into a 1/4 filled jam jar or similar of fluid.........
the assistant will notice the pedal go down to the floor.......he must keep it there while you nip up that nipple.
you say the "up" command and the ass complies......wait for the m/c to take a new mouthful of fluid and repeat process.
take you time and communicate with each other else you will have to start again. remember you are in command.
did the fluid level in the m/c res rise when you pushed the caliper pistons in?? and where they stiff or go back in with thumb ( if not heavy ) pressure with the res cap off??
there is a very small ( tiny ) hole in the m/c bores to the res for "recouperation" or return of fluid when the brakes are released or get hot etc.....else they with drag and possible not release at all!! if that is blocked. if it is blocked then bleeding can be problematic.
ps never let the m/c res fluid level drop too much else you will pump air etc!!!!!!
pps a syringe full of new clean fluid can be used to "wash" the black crap on the m/c res floor and suck that out, rather than have all that crap be pumped thru the system..........also leave time for an "airation" or tiny tiny air bubbles in the res fluid to rise and pop else you will pump that thru the system as well !! or buy a pressure bleeder.....and do it single handed.
thanks for that very good description the garage have said theres airs in the rears but there not willing to bleed them incase the rear nipples snap
Tell them its there fault the air is there and to get it sorted
It's not their fault...they didn't change the front one.
They've got a point tbh, the rears usually snap...
yes, that is a real danger and of course would be the garages fault as its their car!?
so, soak in penetrant and leave ( go prey for an hour ), come back and try to release the nipples with out them shearing off!
hot air may help.........if they shear off, use mig method, drilling as a last resort!!!!!!
mig method:
remove caliper from car and mount steady in vice, clean sheared off remains as best as possible and weld a blob to the sheared nipple in caliper, allow to cool and repeat. be care full not to weld the nipple remains to the caliper!!!!!!!!!
when blobs are big enough ( say 3 blobs ) weld a prepared bolt ( suitable sized bolt with a tapered end ) to the blob, and gently try and release......if it shears off try again.
ok, a different way......remove pads and pump out piston as much as you dare, clamp hose and undo a union a bit and push piston back in, repeat till no air comes out.
I normaly weld a M12 or M16 Nut to them in place, but try roasting the nipple with gas if it is not already snapped
Just bleed the rears off the brake pipe if the nipples do snap. But give the nipples a few taps with a hammer and then try them
(15-11-2014, 02:27 PM)Frosty Wrote: [ -> ]Just bleed the rears off the brake pipe if the nipples do snap. But give the nipples a few taps with a hammer and then try them
This is what the garage did when I snapped one of mine (well Rowells lol
). Seemed to work just as well but didn't trust myself doing it that way lol.
It's not to bad doing it off the brake pipe. It just requires 2 people ideally and does tend to make a mess with fluid going everywhere. I've had to do it a few times with the reputation of the nipples snapping off on 306 rear calipers
(15-11-2014, 08:13 PM)Frosty Wrote: [ -> ]It's not to bad doing it off the brake pipe. It just requires 2 people ideally and does tend to make a mess with fluid going everywhere. I've had to do it a few times with the reputation of the nipples snapping off on 306 rear calipers
Best way to avoid snapping nipples? Dont work on 306s
its what I try to do as much as possible, havent snapped a nipple yet
although when I put new front discs and pads on mine, i though id flush the brake fluid through and one of the rears felt like it was gonna snap, so didnt do that one lol