Fairlane Has Brakes Then No Brakes Then Has Brakes!!!

CONGO MILLENNIUM · 16-03-2012, 10:50 PM

The brake pedal lost pressure today so I stopped and checked the fluid level which was full. I restarted the car the brake warning light was on and the pedal was very spongy, almost going to the floor. I had not lost the brakes completely so I cautiously continued my journey home. After about 5 klms brake pedal pressure started to improve by the time I had arrived home the brake warning light was off, braking power was good and felt normal. I rechecked the fluid (still full ) servo booster hose was connected and there appeared to be no fluid leaks at the callipers.
Any ideas would be much appreciated cheers

**Whoosha** · 16-03-2012, 11:05 PM

Sounds like it may be the piston seals that run between the front to rear lines inside the master cylinder , I would be getting it checked out straight away by a brake shop , to late when you have choofed the rear of some one

FGII-XR6 · 16-03-2012, 11:13 PM

could be the abs unit intermittantly allowing fluid pressure to be released

CONGO MILLENNIUM · 17-03-2012, 12:10 AM

Quote:

Originally Posted by Whoosha

Sounds like it may be the piston seals that run between the front to rear lines inside the master cylinder , I would be getting it checked out straight away by a brake shop , to late when you have choofed the rear of some one

Yes it certainly needs to be checked by brake technician asap.

CONGO MILLENNIUM · 17-03-2012, 12:17 AM

Quote:

Originally Posted by au3xr6

could be the abs unit intermittantly allowing fluid pressure to be released

I was thinking it could be the ABS, if it is faulty surely the ABS warning light would come on?

FGII-XR6 · 17-03-2012, 07:48 PM

Quote:

Originally Posted by gazxr6

I was thinking it could be the ABS, if it is faulty surely the ABS warning light would come on?

if it was electrical yes but if it was seals maybe not

4ford · 17-03-2012, 09:54 PM

For my money...definitely the master cylinder...

Get an exchange unit from a reputable dealer, install it, bleed all the brakes, and you will be fine!

You're looking at about 2 hours work for someone that's not proficient at doing these!

Cheers,
4ford

svo supporter · 18-03-2012, 01:19 AM

How long has it been since the brake fluid has been changed?

Look at the colour and if it's chocolate brown, there's your problem. Had the same issue as you described, with one of my cars. Changed the fluid and no problems 2 months later.

5.0 ED · 18-03-2012, 12:16 PM

I have had issue's with ABS module where by you get next to no brakes at times, but the pedal is rock hard when it happens, cause the abs unit is blocking fluid flow, if your pedal just drops to the floor, then it wont be the ABS unit, unless it was leaking, if you think about it the fluid has to go somewhere, if the abs unit is faulty it can block it, but it cant bypass the pressure only direct it further down the path.

If the pedal just drops to the floor then i'd be looking at your master cylinder like others have already mentioned.

CONGO MILLENNIUM · 18-03-2012, 05:42 PM

Quote:

Originally Posted by 4ford

For my money...definitely the master cylinder...

Get an exchange unit from a reputable dealer, install it, bleed all the brakes, and you will be fine!

You're looking at about 2 hours work for someone that's not proficient at doing these!

Cheers,
4ford

Yes I feel the master cylinder needs to be replaced which in turn means new fluid, I have no idea if the fluid has ever bee changed.
Would old fluid alone cause the brake pedal to go to the floor?
When bleeding the braking system is there a proceedure to follow to remove the old fluid from ABS unit and lines etc?

svo supporter · 18-03-2012, 11:36 PM

When a M/C goes, the brake pedal height is straight to the floor and doesn't by some miracle come back good. The pedal stays on the floor.

If the fluid is old, it tends to boil quicker, which means the pedal feel is crap. When the fluid cools off, the pedal height comes back, along with the feel.

The same thing applies if you use standard fluid and thrash the car round on a race track. The fluid boils, the brake pedal feel is crap.

But hey, you want to replace the M/C, go ahead. Just think about what I have written and apply it to what you've experienced. Also query people that have raced their car, with standard brake fluid and ask them how their brake pedal feel is after they've done 3 or 4 hard laps, then what it is like when the fluid has cooled down and apply it to your current experience..

CONGO MILLENNIUM · 19-03-2012, 11:42 AM

Quote:

Originally Posted by svo supporter

When a M/C goes, the brake pedal height is straight to the floor and doesn't by some miracle come back good. The pedal stays on the floor.

If the fluid is old, it tends to boil quicker, which means the pedal feel is crap. When the fluid cools off, the pedal height comes back, along with the feel.

The same thing applies if you use standard fluid and thrash the car round on a race track. The fluid boils, the brake pedal feel is crap.

But hey, you want to replace the M/C, go ahead. Just think about what I have written and apply it to what you've experienced. Also query people that have raced their car, with standard brake fluid and ask them how their brake pedal feel is after they've done 3 or 4 hard laps, then what it is like when the fluid has cooled down and apply it to your current experience..

The Fairlane has only done 145000 klms but it is 13 years old so the fluid could be the same age.

How do I go about changing the brake fluid??

svo supporter · 19-03-2012, 06:57 PM

Being a dual circuit system, crack open both back bleeder nipples and pump all the fluid out. Once the M/C is dry of fluid, get a rag and wipe it clean.

Once clean, put fresh fluid in and pump the brakes (with bleeders open) until you have fresh fluid coming through. Just be cautious not to run out of fluid in the M/C.

Once you have clean fluid, close the bleeder nipples.

Pump the brake pedal up until you have a hard pedal, and starting from the left rear, open the bleeder up and allow all the air to escape. Continue this procedure until there is no more air coming from the L/R, move to the R/H rear and re-start the procedure.

Once the rear brakes have all the air out, re-start the cleaning procedure on the fronts.

When bleeding the fronts up, start at the L/F and finish at the R/H front.

Hopefully you can follow this and I'm very confident your brake issues will be solved.

4ford · 20-03-2012, 01:45 PM

Don't forget, when bleeding brakes on any car that hasn't been fitted with a new/exchange master cylinder, ALWAYS remember NOT to push the brake pedal right to the floor at ANY time.

ONLY push the pedal as far down as it would normally go in normal use.

The reasoning for this is that, within the m/cylinder bore, the millions of times the piston has moved back and forth has created a very small 'lip' at it's forwardmost point of travel.
If you push the pedal past this point, you risk rolling the piston seals and "that's it" for the master cylinder, you will not get any 'hard pedal' at all, and it will have to be removed and overhauled!

With a new/exchange m/cylinder, that's not a problem!

Cheers, 4ford

mik · 21-03-2012, 12:53 PM

brake fluid needs to be changed periodically, brake fluid absorbs water , water in hydraulics is not a good thing, apart from the fluid boiling and turning to steam, water attacks some materials over a period of time, probably at least every couple of years for a fluid change.

CONGO MILLENNIUM · 21-03-2012, 08:54 PM

Quote:

Originally Posted by svo supporter

Being a dual circuit system, crack open both back bleeder nipples and pump all the fluid out. Once the M/C is dry of fluid, get a rag and wipe it clean.

Once clean, put fresh fluid in and pump the brakes (with bleeders open) until you have fresh fluid coming through. Just be cautious not to run out of fluid in the M/C.

Once you have clean fluid, close the bleeder nipples.

Pump the brake pedal up until you have a hard pedal, and starting from the left rear, open the bleeder up and allow all the air to escape. Continue this procedure until there is no more air coming from the L/R, move to the R/H rear and re-start the procedure.

Once the rear brakes have all the air out, re-start the cleaning procedure on the fronts.

When bleeding the fronts up, start at the L/F and finish at the R/H front.

Hopefully you can follow this and I'm very confident your brake issues will be solved.

How much bake fluid is required for a complete refresh?

Would Castrol Response Dot 4 brake fluid be suitable for the Fairlane as I have a new 500ml container?

Also what size plastic tubing fits the bleeder nipples?

svo supporter · 21-03-2012, 09:31 PM

Quote:

Originally Posted by gazxr6

How much bake fluid is required for a complete refresh?

Would Castrol Response Dot 4 brake fluid be suitable for the Fairlane as I have a new 500ml container?

Also what size plastic tubing fits the bleeder nipples?

2 to 3 bottles....so that's 1.8 litres max

Yup, the fluid you've suggested will be fine.

Not sure on tubing size. As long as it covers the bleeder nipple, it'll be fine.