Brake bleeding

[nero279]

OK, so who's mechanical and bored and wants to talk me through bleeding the brakes step-by-step?

Here's the deal, the rear axle on my new truck's in shite condition, and needs a new wheel bearing. The axle on the breaker is in far better condition anyway and had both bearings and a complete brake overhaul in the last year, and also still has a working LSD. Both axles are G285s.

I'm fine with the swapping of the axles, just need some guidance with sorting out the braking system once it's done. So a walkthrough of the best way to disconnect the brakes & handbrake, then reconnect them once i've swapped the axle would be fantastic.

Cheers

[nero279]

Bump

Anyone? ideas?

I need to swap them over tomorrow, she goes on friday.

[fatfires]

cant help on the swaping but I was told and it worked for me just bleed the brakes using gravity, tube from the nipple to a jar with some fluid wait for bubbles to stop - tighten up....done, no need to pump anything

[nero279]

thanks tony, will give it a go.

Any other tips?




- One other thing, for the breaker will adjusting the LSV brake bias thingy all the way before i disconnect the brake line, seal off the rear brakes off completely, putting 100% bias on the front and leave some sort of braking intact on it for when we move it friday? Handbrake's cable operated isn't it? so i'd still have that if i didn't bother putting the LSV to axle line back on wouldn't I?

[plumb bob]

Hey Ian, I've got a brake bleedy non return thingy that makes it an easy one man job, or a very easy two man job, if you like, I'll come down at the weekend, or next weekend, and give you a hand.

I've got some tools too if it helps.

[MattF]

Tony's suggestion should work fine. Wind the adjusters down so that the piston is down into the cylinder, (less air to possibly expel), then pop a length of pipe onto the bleed nipple, other end into a jar with some clean fluid in, (making sure the other end of the pipe is below the level of the fluid), crack open the bleed nipple and keep pumping/topping up until no air bubbles are visible coming from the pipe in the fluid in the jar.

With regards to bleed order, go from the furthest cylinder first to the closest cylinder last, (in relation to the master cylinder).

[nero279]

Hey Ian, I've got a brake bleedy non return thingy that makes it an easy one man job, or a very easy two man job, if you like, I'll come down at the weekend, or next weekend, and give you a hand.

I've got some tools too if it helps.

Might take you up on that rob, see how it goes today. I'll try and at least not screw it up too badly and fill the whole system with air

[MattF]

Provided you make sure that you don't let the master reservoir run empty, you shouldn't have any worries there.

[nero279]

Provided you make sure that you don't let the master reservoir run empty, you shouldn't have any worries there.

arse i shouldn't of just read that again, i'll have to go check it again now seemed to find a happy level earlier but i topped it up and it started dripping again.

[Albannach]

To bleed them properly you need 2 people. One person in the cab, the other at the wheel being bled.

Starting with the wheel furthest from the master cylinder and work towards the closest wheel to the cylinder. On a surf it's NSR, OSR, NSF then OSF.

Get the person in the cab to pump the pedal until they feel pressure, once they feel pressure, hold the pedal down. Whoever is at the wheel, opens the bleed nipple until the pedal goes to the floor. Hold the pedal on the floor until the nipple is closed, then pump up the presure at the pedal again. Repeat this until there is no air seen at the nipple. Move on to the next wheel and repeat.

The air is expelled using the theory that air in a liquid will always go to the point of least pressure (e.g. bubbles rising in a beer). Unless you can create a point of low pressure, the air will not move. Pumping the pedal to a presure then releasing it at the nipple is the best way to create large pressure drops and ultimately expel all the air.

There are bleding kits available, but they are not as quick or effective as the method above.

[nero279]

well today's progress, not too bad, but expecting to do my first ever axle swap, alone, start to finish in time to go for a round of golf this afternoon may have been a touch ambitious

tips for next time:

1) it's not technically demanding or difficult, but it's ###### physical. Not sure what the axle itself weighs, but with a wheel and tyre on each end weighing in over 30kg each, it ends up ferkin heavy

2) removing the drums to release the handbrake cable is still easier on the 2nd truck if you release the handbrake first! Yes i tried to take the drums off the breaker with the handbrake on, then repeated the same procedure on the other truck too

3) the axle might come off a truck with no bumpers or mud flaps and all that stuff on it with the wheels on so you can just roll it out, round and line it back up to the other truck, but it don't go back on the truck you just had to drop the wheels back off and roll the other axle out on a pair of trolley jacks to get it low enough to pass the mud flaps and bumpers and all that

4) it becomes much easier 2nd time around, as with most jobs. It's also much easier with 2 of you.

5) Plan for it to take two days, at the moment i've got 2 trucks on axle stands on my drive, one has an axle half fitted (well it's under the truck and the lower control arms are loosely bolted up anyway), the axle for the other one's in me back garden. I gotta work tomorrow and someone's coming to pick up the truck with the axle half fitted on friday.



All in all not a bad days work i don't think, still got a bit more to go though, and i missed me golf this afternoon

[nero279]

Ok, all done axles swapped. Gotta check the propshaft as it's vibrating like a good un so guess it's not centred properly or something.

Still got problems with bleeding the brakes though, any more tips? And a couple of questions. Should it be done with handbrake on or off (or does it not make the blindest bit of difference)? What about the bleed nipple on the LSV? Should i bleed that aswell, and take it you do it it the same as you would bleeding at a wheel cylinder? Where in the sequence does it fit? After rears i assume?

[The Ferret]

Chillitt knows all about bleeding brakes! Especially on his Kawasaki!!!!!!!


Ferret

[fatfires]

the vibration doesn't sound too good, perhaps a worn UJ has moved out of line - why not swap props over?
I dont know if I was lucky or what but when I did my rear bearings I swaped to braded hoses, did the usual withtube jar and fluid but literally just opened the nipple and let gravity do the job - no pumping, hold pedals down or anything like that, seem to remember if was Barry @roughtrax who told me, but they bled out a dream and havn't had to touch them since.