Renewing/changing brake fluid, bleeding sequence?

[Millie Master]

I am just about to change the brake fluid on'Millie' as it is almost 4 years since I last did so and that I noticed the other day that it was looking quite dark.

My van is a 2008 Renault Master and I can't recall what the bleeding sequence is...................... my memory is suggesting that it is the same sequence as my cars which is OSR, NSR, NSF, OSF, but does anyone know for certain please?

Many thanks

Phil

 

[helmit]

Hi Phil the bleeding sequence is start at the furthest away and work towards the master cylinder. Jim.

 

[Squiffy]

That is the way I have always bled systems, though there is suggestion that it should be O/S/R then N/S/F then N/S/R and finally O/S/F, the reason being that some brake systems work on the principle that should one side fail the other side will bring the vehicle to a stop in a relatively straight line. Some other vehicles used to work front working together and rears working together so if the fronts failed the rears would stop the vehicle and vice versa. There is a far larger braking effort to the front brakes than to the rear brakes, the rear brakes are mainly used to stop the vehicle snaking ( Rear of vehicle swinging round ). This is why rear brake pads always out last front brake pads by a factor of three. But as for bleeding I have done it in all sorts of sequences and never failed to bleed the brakes properly, unless of course there was a problem with the master cylinder or one or more of the slave cylinders. Phil

P.s I have on many occasions successfully bled brakes where the slave bleed nipple has been snapped off by bleeding through loosening the hydraulic brake line at the slave cylinder union.

 

[trevskoda]

Be carful as some times working a old master cyl as i did doing mine last year lead to it failing and brake pedal going down slow to floor,in the end i got a new unit in germany for about 60/70 bucks as iveco here wanted £400.

 

[time4t]

I was told many years ago, to never shove the brake peddle to the floor when bleeding the brakes, because there is a high risk of reversing the seals!

I've always bled the system by starting at the wheel furthest away from the master cylinder.

My sharan has been a real bugger to bleed & I abandoned it after I got a good brake peddle but the servo started hissing on the down stroke.
New servos with a fork type connector to the master cylinder are rarer the rocking horse sh-t

Phill

 

[Squiffy]

I was told many years ago, to never shove the brake peddle to the floor when bleeding the brakes, because there is a high risk of reversing the seals!

I've always bled the system by starting at the wheel furthest away from the master cylinder.

My sharan has been a real bugger to bleed & I abandoned it after I got a good brake peddle but the servo started hissing on the down stroke.
New servos with a fork type connector to the master cylinder are rarer the rocking horse sh-t

Phill

Phill, I have in the past got the diaphragm from another similar servo and fitted it to the broken servo, this is of course only if the servo casing is able to be split into two, this was viable on servos in the 70's to 90's but with all this throw away society it may not be possible with yours. If you study yours you might find that it is possible to squeeze and twist the front face cover to get to the servo diaphragm. Phil

That is after you have removed the master cylinder and if I remember correctly the studs that hold the master cylinder onto the servo, its been along time since I was involved.

 

[time4t]

Phill, I have in the past got the diaphragm from another similar servo and fitted it to the broken servo, this is of course only if the servo casing is able to be split into two, this was viable on servos in the 70's to 90's but with all this throw away society it may not be possible with yours. If you study yours you might find that it is possible to squeeze and twist the front face cover to get to the servo diaphragm. Phil

That is after you have removed the master cylinder and if I remember correctly the studs that hold the master cylinder onto the servo, its been along time since I was involved.

Yes your're right, I've already been down that route but on inspecting the case, I discovered that it's spot welded all the way around & the welds are very close to the pressure chambers casing.

But thanks for the suggestion.

Phill

 

[Millie Master]

My job is all done now, it took me about 45 mins. to do everything.

I was amazed how dirty all the fluid was that came out and by dirty I mean it was of a far darker colour than the new fluid I was putting in, but I was pleased/relieved to see that there weren't any small black particles in the fluid that came out.

I now have a very good solid pedal and so 'Millie' is ready for her next voyage, this time to Welsh/Wales.

Phil