Bleeding Brakes?

[MAT_8N]

anyone one know which order i bleed the brakes in?

its a 96/97 ser 3 ls 400.

do i start at the back and then the front or is there an order? just put new pads in and it still feels a litttle spongy.

ta

[MAT_8N]

just found out

bleed master cylinder first then,

right rear

left rear

right front

left front.

[Tony-Bones]

Historically you would bleed from the nearest/shortest feed from the master cylinder then work your way back?

[MAT_8N]

don't you do it from the longest and work the otherway?

i've got one of them cd manuals and they recomend the back to front method?

i'm sure i've always done it from back to front? its been that long and that was on a single circuit 1955 vw beach buggy!!

[MacRS200]

I would agree with the above. On a RHD car would be NSR, OSR, NSF and last OSF.

[Haylands]

just put new pads in and it still feels a litttle spongy.

ta

It will feel a bit spongy untill they bed in, do this gently over a few hundred miles and the pedal will be fine, at the moment only part of the pad is touching the disc when you break, the pedal feels spongy because you are in effect bending the pads to fit the disc.

It may be a good idea to change the brake fluid anyway as it will absorb moisture over time, you do this by bleeding the furthest brake first, bleed it untill most of the fluid has gone (do not let it go completely) then top up with fresh fluid, then bleed again untill frsh clean fluid comes out, keep topping up and do all the four wheels untill it is clean from each one. Use the correct rated fluid, check your handbook, probably dot4, do not use synthetic fluid, if you want to change to this you will have to change all the seals in the brake system. There would be no benefit on a standard car anyway....

Good Luck

Pete

[MAT_8N]

just put new pads in and it still feels a litttle spongy.

ta

It will feel a bit spongy untill they bed in, do this gently over a few hundred miles and the pedal will be fine, at the moment only part of the pad is touching the disc when you break, the pedal feels spongy because you are in effect bending the pads to fit the disc.

It may be a good idea to change the brake fluid anyway as it will absorb moisture over time, you do this by bleeding the furthest brake first, bleed it untill most of the fluid has gone (do not let it go completely) then top up with fresh fluid, then bleed again untill frsh clean fluid comes out, keep topping up and do all the four wheels untill it is clean from each one. Use the correct rated fluid, check your handbook, probably dot4, do not use synthetic fluid, if you want to change to this you will have to change all the seals in the brake system. There would be no benefit on a standard car anyway....

Good Luck

Pete

that sounds about right. looking at the front disc its only touching the top half. i thought it was because there was air in the system so it wasn't working properly.

i was gonna bleed the system right through anayway as i dont think its been changed for about 60k miles!!

am i better off waiting a few hundred miles before i do it?

cheers

Matt

oh yea, the manual cd manual says its dot 3 and a load of numbers. i'll double check with my ls 400 manual i got with the car.

[Haylands]

Mat

Dot3 should be fine

You can do it now or later it won't matter, make sure its new sealed brake fluid and DON'T let the reservoir run dry

Pete

[Tony-Bones]

I would agree with the above. On a RHD car would be NSR, OSR, NSF and last OSF.

I sit corrected

[Neofate]

Historically you would bleed from the nearest/shortest feed from the master cylinder then work your way back?

Actually it is reverse -- and it is the proper way on every vehicle manufactured (technically)

Begin at the corner furthest from the driver and proceed in order toward the driver. (Right rear, left rear, right front, left front.)

Either way the job will get done. If you bled in any order you wouldn't get much of a different result, if any, if bled properly. (in my experience)

[Neofate]

Also bedding is very important --

I stress proper bedding to prevent rotor warpage. I would say a significant amount of rotor warpage is due to ZERO bedding on a brake job. It is not told to the customer by the brake shop, and the customer probably wouldn't follow it even if told :) -- But for the lucky few who actually know what it is, it helps alot.

Here is an example: *Note seems to be for front rotorr/pads only* -- But those are what do 70% of our braking and the rotors that warp 90% of the time.

To ensure maximum braking performance and long life, new brake pads must be broken in properly upon installation.

The correct process of breaking in the pads guarantees that the new brake pads and rotors work to maximize the braking efficiency. In order to function optimally, Organic, Semi Metallic, and even Ceramic brake pads must develop a friction coal on the pad and rotor surface.

The friction coal is created at a temperature of approximately 550°F. It is very important that this temperature is reached in a manner that does not overheat the brakes. The gradual heat process generates the high temperatures that penetrate the surface of the brake rotors and pads.

This process is even more important when installing new brake rotors since the rotor often needs to go thru a few heat cycles to properly develop the hardness in the metal casting. A slow and careful heating and cooling process guarantees a good mating of both the pads and rotors.

The bedding in/break in procedure should be done as follows:

Make sure you perform this process in a very safea and controlled environment. The following process should be done in a safe place that has no other vehicles or pedestrians.

Drive at approx. 35 to 40 mph for about 500 yards for solid rotors and 800 yards for vented rotors while slightly dragging the brakes. Use light braking pressure with the left foot while using the right foot to depress the accelerator to maintain the 35-40 mph speed. This will allow the brake temperature to slowly and evenly build up to 550°F to 600°F.

Once you have driven the appropriate distance applying the brakes, then remove the left foot form the brake petal for approximately ¼ mile maintaining the same speed without braking. This will allow the pads and rotors to evenly cool down. Repeat this step one more time, then perform a normal brake application from 40 mph to complete stop. Do Not make a panic or a sever stop at this time!

This break in process is only suitable for the front brakes and not the rear. This is due to the braking distribution of front and rear brakes. Using this process for rear brakes would result in overheating and warping of the front brakes.

[MAT_8N]

do not use synthetic fluid, if you want to change to this you will have to change all the seals in the brake system.

Good Luck

Pete

in the shop i normally go to they only have sythetic based fluid in stock. he said it would be hard to get mineral fluid now!

he also said that it would be ok to go to synthetic but not then to go back to mineral?

is this right? i dont want to do the wrong thing.

i'm in no rush to do it, i just want to do it right.

thanks for all the advice.

[PCIronmike]

Put it on a ramp Mat and gravity bleed the whole lot in one go , just keep the reservoir topped up and dony spill any fluid from the bleed valves onto anything painted mate , Shame your so far away coz I have a pressure bleeder that works off of the Battery , its the nuts an I'd do it for ya gladly .

Regards

Paul. B)

[Haylands]

do not use synthetic fluid, if you want to change to this you will have to change all the seals in the brake system.

Good Luck

Pete

in the shop i normally go to they only have sythetic based fluid in stock. he said it would be hard to get mineral fluid now!

he also said that it would be ok to go to synthetic but not then to go back to mineral?

is this right? i dont want to do the wrong thing.

i'm in no rush to do it, i just want to do it right.

thanks for all the advice.

Hmmmmmm someone is telling porkies and I don't think its me.... but I have been wrong before...

Pete

[Haylands]

Also bedding is very important --

I stress proper bedding to prevent rotor warpage. I would say a significant amount of rotor warpage is due to ZERO bedding on a brake job. It is not told to the customer by the brake shop, and the customer probably wouldn't follow it even if told :) -- But for the lucky few who actually know what it is, it helps alot.

Here is an example: *Note seems to be for front rotorr/pads only* -- But those are what do 70% of our braking and the rotors that warp 90% of the time.

To ensure maximum braking performance and long life, new brake pads must be broken in properly upon installation.

The correct process of breaking in the pads guarantees that the new brake pads and rotors work to maximize the braking efficiency. In order to function optimally, Organic, Semi Metallic, and even Ceramic brake pads must develop a friction coal on the pad and rotor surface.

The friction coal is created at a temperature of approximately 550°F. It is very important that this temperature is reached in a manner that does not overheat the brakes. The gradual heat process generates the high temperatures that penetrate the surface of the brake rotors and pads.

This process is even more important when installing new brake rotors since the rotor often needs to go thru a few heat cycles to properly develop the hardness in the metal casting. A slow and careful heating and cooling process guarantees a good mating of both the pads and rotors.

The bedding in/break in procedure should be done as follows:

Make sure you perform this process in a very safea and controlled environment. The following process should be done in a safe place that has no other vehicles or pedestrians.

Drive at approx. 35 to 40 mph for about 500 yards for solid rotors and 800 yards for vented rotors while slightly dragging the brakes. Use light braking pressure with the left foot while using the right foot to depress the accelerator to maintain the 35-40 mph speed. This will allow the brake temperature to slowly and evenly build up to 550°F to 600°F.

Once you have driven the appropriate distance applying the brakes, then remove the left foot form the brake petal for approximately ¼ mile maintaining the same speed without braking. This will allow the pads and rotors to evenly cool down. Repeat this step one more time, then perform a normal brake application from 40 mph to complete stop. Do Not make a panic or a sever stop at this time!

This break in process is only suitable for the front brakes and not the rear. This is due to the braking distribution of front and rear brakes. Using this process for rear brakes would result in overheating and warping of the front brakes.

This is not recommended in the UK, we use different specification brake material here and the only thing that will happen if you do the above will be to glaze the pads and put strain on the torque converter.

Many gentle applications are better than all at once!!!

Pete

[MAT_8N]

apperently dot 3/4 are sythetic based.

if it was mineral it would be called LMH or something, like what they use in citreons and old rollers and jags(more hydraulic based)

dot3/4 have always been synthetic but haven't had it on the bottles until quite recently.

the number in my manual for brake fluid is SAE J1703 dot 3 and on all the dot 3 sythetic based bottles i've seen have that number.

its the common brake fluid. i dont think lexus use anything different or older?

can anyone else confirm this please

thanks

[lutonmatt]

i always do it o/s/r n/s/f o/s/f n/s/r

[Haylands]

apperently dot 3/4 are sythetic based.

if it was mineral it would be called LMH or something, like what they use in citreons and old rollers and jags(more hydraulic based)

dot3/4 have always been synthetic but haven't had it on the bottles until quite recently.

the number in my manual for brake fluid is SAE J1703 dot 3 and on all the dot 3 sythetic based bottles i've seen have that number.

its the common brake fluid. i dont think lexus use anything different or older?

can anyone else confirm this please

thanks

Mat

We are getting confused with terms here....

All "normal" dot 3/4 fluid is glycol based with various other additives, you could call it synthetic because it is a mix, I was refering to the fully synthetic silicon brake fluid that is getting more widely available. The claims on the bottles are vast, this stuff requires you to change all the seals in the brake system as it will react with the old fluid and rot them. You are perfectly alright using SAE J1703 dot 3 fluid it is standard brake fluid. Mineral based fluid was dot 2 and is no longer widely available... so go for it and good luck

Pete

[PCIronmike]

I don't want to put the cat among the pigeons here but with all disc replacements care should always be taken when braking for the first initial periods due to the new discs never having heat stressed through them before , if you ignore this and brake hard at speed you will most definately warp the disc and will have to replace them again .

Regards

Paul.

[Haylands]

Good advice but Mat has only changed the pads......

[MAT_8N]

cleared that up!

well they work!!!!! i nearly had a crash tonight! some dumb women pulled out on me and i had to emergancy stop. it would have been a big impact without the abs, i steered away at the very last moment. i ended up looking out my passenger side window at the woman!!!!

and it was all wet too.

thank god for good cars with good brakes.