Brakes Soft After Hel Line Install

[SargeRX8]

Hey all,

I installed a set of HEL brake lines on my car. Been following all the guides for bleeding with a helper. I thought I got most of the air out but the brake pedal is strange. On the first press its mushy and will hit the floor but an immediate press after the brake feels very nice and firm. Then if I release for about 5 seconds, it will do the same thing, soft on the first press then nice and firm afterwards.

I took it to a shop and he suggested I do a gravity bleed and stated that something might not be aligned properly with the calipers/rotors.

I did notice something is that my rotor sits loose(front only) when the wheel is off. Could this affect the bleeding? The rotor will most likely flex a little out of balance. I will attempt my next bleed with lugs tightened on the bolts to hold the rotor stiff.

Does anyone else have any other ideas or suggestions? There are no leaks in the system.

[PM-R33]

What method are you using to bleed the brakes?

[simpletool]

Try bleeding with the engine on and pumping the pedal, might get air out of the system. If this doesn't work try gravity bleeding. I always bleed with 2 bolts (out of 5) on the rotor.

Remember to close the bolt when still pushing down on the peddle (2 person job). Or gravity drain to finish.

Edited January 24, 2011 by simpletool

[SargeRX8]

This is how I did it. My first attempt was with the car ON but with this my engine sounded like it was going to stall. I managed to get alot of air out but not sufficient.

The next day I tried again. I would start with the rear passenger then rear driver then front passenger and front driver. I will have my assistant pump the pedal 3 - 5 times hard then hold down firmly then crack the nipple for about half a second into a bleeder line. I will then seal it up and ask them to do it again. I then proceed to the next caliper in the order above. I ensure my fluid is always well above minimum. I ensure my assistant will hold the peddle firmly to the floor and after I give the call that I have tightened up the bleeder, they would them remove their foot off the brake. I did not hold any of the rotors down and I think this may have had an effect on the overall bleed.

It does look like clean new fluid is now in the system though. I managed to get quite a large jolt of old fluid today which did surprise me(it was new and clean then a shot of dirty old green fluid shot through).

I'm using Motul dot 5.1(its suitable for all dot 3/4/5.1 applications).

I do intend on changing my brake pads very soon with some QMX pads I think they were called so I'm really hoping I wouldn't have to go through this shit again lol.

Edited January 24, 2011 by SargeRX8

[Deano 1]

sounds like you found the problem. it strang that the dirty old fluid got between new and old...

[PM-R33]

Honestly bleeding brakes is a pain in the ass and I hate doing it.

[75coupe]

I will have my assistant pump the pedal 3 - 5 times hard then hold down firmly then crack the nipple for about half a second into a bleeder line. I will then seal it up and ask them to do it again.

Shouldnt it be crack the nipple pump peddle till new clear fluid is seen and on last pedal downstroke seal nipple..??

Do you have ABS?

[75coupe]

I did not hold any of the rotors down and I think this may have had an effect on the overall bleed.

It does look like clean new fluid is now in the system though. I managed to get quite a large jolt of old fluid today which did surprise me(it was new and clean then a shot of dirty old green fluid shot through).

I do intend on changing my brake pads very soon with some QMX pads I think they were called so I'm really hoping I wouldn't have to go through this shit again lol.

It wouldnt matter if the rotors were being grabbed by the calipers or not, your bleeding fluid piston position wouldnt matter, but if the rotors are still loose then there is something wrong.

If your still getting dirty fluid through occasionally then your bleeding wrong

changing pads wont have any impact on brake fluid or needing to bleed...

I usually bleed the whole system by myself, using a clear tube that fits snug on the nipple and have it go up and over the top suspension arm into a clean glass jar that way air bubbles rise up to the top when they come out and when I release the pedal it only sucks in clean expelled fluid... Ive done this many times on a few different cars and always works fine, Ive flushed whole systems this way by myself...

[Moodles2]

Make sure the ABS unit is being bled, also are you bleeding them in the correct order (Nissan specifies that all 4 corners be done in a certain order)

[DVS JEZ]

start again with new fluid if there is still old fluid coming through, as above start the furthest away from the master but this time open the nipple and just keep slowly pumping the pedal all the way to the floor (KEEP TOPPING UP THE FLUID DONT LET IT GO BELOW THE LOW LINE) until the fresh fluid comes through,

then do the pump the pedal until hard and while holding pedal pressure down crack the nipple and lock it up before the pedal reaches the floor.

do this on all corners as you did.

if you by accident let the fluid go below the low line chances are you will have to start again.

hope this helps

[blind_elk]

Have you bled the master cylinder? It should be bled first, then bleed the wheels (LR, RR, LF, RF)

[Smegul]

I thought to bleed the brakes, put pressure on the pedal, open nipple until pedal stops, close nipple, release pedal, repeat over and over.

[robbo_rb180]

if you can't get it right doing it yourself take it to a mechanic. at least you know it will be done properly.

you don't want the pedal to be like when you have to pull up quickly.

[75coupe]

I reckon learn a good method, save money doing things yourself and get the satisfaction as well...

its not a hard thing to bleed brakes, its one of the basic car maintenance things that every enthusiast should know.

just think it out exactly what your actually trying to achieve so understand what the process is and why its done a particular way then you'll be able to complete it correctly...

plus it always helps if you have someone who knows it to show you once or twice...

[DVS JEZ]

I thought to bleed the brakes, put pressure on the pedal, open nipple until pedal stops, close nipple, release pedal, repeat over and over.

start again with new fluid if there is still old fluid coming through, as above start the furthest away from the master but this time open the nipple and just keep slowly pumping the pedal all the way to the floor (KEEP TOPPING UP THE FLUID DONT LET IT GO BELOW THE LOW LINE) until the fresh fluid comes through,

then do the pump the pedal until hard and while holding pedal pressure down crack the nipple and lock it up before the pedal reaches the floor.

do this on all corners as you did.

if you by accident let the fluid go below the low line chances are you will have to start again.

hope this helps

[SargeRX8]

I do not have an ABS unit in my car.

There are no bleed nipples on the master cylinder... How necessary is it to hold the jar above the nipple? I just flex the pipe up so the bubbles travel up.

When I crack the nipple, my assistant usually will hit the floor as soon as the pressure drops, thats when I seal it back up and then they release the pedal sucking in fresh fluid from the master resevoir. Is there any point trying a gravity bleed? The mechanic suggested I try this before taking the car to him.

[DVS JEZ]

Try as i said. U dont have to have the bleeder higher i have never done that. Try and keep the bleeder hose in a bottle with asmall amount of fluid at minimum. Empty the bottle if it gets full obviously

[Deano 1]

I norm also put a 2inch block of wood under the brake pedal so the pedal can't hit the floor, takes a lil longer to pump it though but no chance you can suck any air

[SargeRX8]

I think my problem is air in the master. When I installed the lines I let aol the old fluid drain out from the front passenger caliper. I got someone to pump the pedal until there was nothing coming out. This was a bad move... If there is air in the cylinder, will it come out?

[badhairdave]

I think my problem is air in the master. When I installed the lines I let aol the old fluid drain out from the front passenger caliper. I got someone to pump the pedal until there was nothing coming out. This was a bad move... If there is air in the cylinder, will it come out?

Yes it was and yes it will.

Now you have to bleed the master and that's a messy bitch of a job.

You might get away with just loosening the front brake line, pump the pedal a few times until fluid is seeping past the thread, and then tighten it up. If you are lucky it will clear enough air that you can bleed the rest of the system like you have been doing already. If you are unlucky you may need to bleed the primary (rear most fitting) as well before bleeding. Do both to be sure.

Edited January 25, 2011 by badhairdave