I have 2 problems at the moment:
1. Brakes
The foot brakes don't work. The handbrake works if it's on the furthest notch, the footbrakes work if the handbrake is on and if you pump them a few times. To answer the obvious questions, we gave 'em a full bleed and it half-fixed the problem but it's been progressively worse. Pads are also fine, front and rear and, yes, the car does have brake fluid.
When we bled them out the colour of the brake fluid in the resaviour was grubby as if the fluid had backpumped thru the line. This makes me inclined to think that the one way valve in the master cylender is broken and/or that it's coherent to an underlying problem with the rear brakes.
Has this happened to anyone before?
2. Engine mounts
The car obviously has a problem with mounts, I'm not sure if it's the rear engine mount or the gearbox mount so i'll explain some symptoms: expecially 1st and at the bottom end of second, the car makes a knocking noise under the bonnet, this causes the gearstick to move around. By third tho, she seams to settle down a bit and cruises aloing fine even under full throttle.
Any sort of negative power on the engine causes it to knock and move around as when engine braking or reversing.
Even though they appear to both be fine, I dunno which one it is tho, any ideas?
note - it's not the front mount as it's been replaced
cheers for ya help people, any ideas???
Anarki!
Brakes and engine mounts
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evilgidget
- Posts: 342
- Joined: Tue Apr 13, 2004 10:22 pm
- Location: Newcastle, NSW
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1 - master cylinder faulty. And i know it's a bitch to replace because it's fitted underneath the dashboard. It wasn't cheap or easy to find either... 
2. You need a strut brace with engine steady or some form of strong top engine mount to prevent the engine torque shifting.
F8B EFI turbo - Three pots and a snail.
There is no non-return valve in disk brake systems.
To bleed brakes on your own, get a jar (I use a Nexcafe jar) with a screw top, drill a hole in the top, compatible with plastic tubing that sits tightly on the bleed valve.
Poke hose in to about 2cm of the bottom of the jar. (make sure its a clean dry jar).
Just crack the bleed valve on the wheel you are going to bleed.
Fit plastic hose firmly.
Important- make a loop in the plastic hose, and feed it into a position where it continues on above the loop and tie to a convenitnt place with say a garden wire tie.
Feed the other end into the jar as above.
You can then open the bleed valve a couple of turns, and pump a few times to get the fluid to cover the bottom of the hose. Keep an eye on the level in the master cylinder or you will have to bleed the lot again.
The loop will retain some fluid so the air does not suck back into the cylinder.
Pump 2 or 3 times, hop under, tighten the bleed screw, pump to see if tighter. Repeat as necessary. Usually you can see air bubbles still in the tube if it still has air in it.
Seeing as you have to have the handbrake on to work, and it has to go almost to the limit, I would suggest your rear brake shoes need adjustment, that should cure the handbrake and footbrake problems. Remember these have two leading shoes on each rear wheel, so you have to adjust the front and rear shoe on each rear wheel, just doing one shoe will not achieve anything except wear that one out quicker. Adjust till brakes rub, then pump brakes 2 or 3 times, adjust again. This ensures the shoes are centralised as they will adjust off centre otherwise.
To bleed brakes on your own, get a jar (I use a Nexcafe jar) with a screw top, drill a hole in the top, compatible with plastic tubing that sits tightly on the bleed valve.
Poke hose in to about 2cm of the bottom of the jar. (make sure its a clean dry jar).
Just crack the bleed valve on the wheel you are going to bleed.
Fit plastic hose firmly.
Important- make a loop in the plastic hose, and feed it into a position where it continues on above the loop and tie to a convenitnt place with say a garden wire tie.
Feed the other end into the jar as above.
You can then open the bleed valve a couple of turns, and pump a few times to get the fluid to cover the bottom of the hose. Keep an eye on the level in the master cylinder or you will have to bleed the lot again.
The loop will retain some fluid so the air does not suck back into the cylinder.
Pump 2 or 3 times, hop under, tighten the bleed screw, pump to see if tighter. Repeat as necessary. Usually you can see air bubbles still in the tube if it still has air in it.
Seeing as you have to have the handbrake on to work, and it has to go almost to the limit, I would suggest your rear brake shoes need adjustment, that should cure the handbrake and footbrake problems. Remember these have two leading shoes on each rear wheel, so you have to adjust the front and rear shoe on each rear wheel, just doing one shoe will not achieve anything except wear that one out quicker. Adjust till brakes rub, then pump brakes 2 or 3 times, adjust again. This ensures the shoes are centralised as they will adjust off centre otherwise.
i have bled the brake system thru a number of times now and it's not the problem, although it does fix the problem temporarily. The rear brake shoes have also been adjusted.
As dirty brake fluid backflows into the brake fluid resavoir, this means to me that there is no pressure in the brake lines hence there must be a one way valve in the master cylender.
I believe that the age of the brake fluid in the rear lines would also have a bearing on the effectiveness of the brakes.
Is that correct?
cheers,
Anarki!
As dirty brake fluid backflows into the brake fluid resavoir, this means to me that there is no pressure in the brake lines hence there must be a one way valve in the master cylender.
I believe that the age of the brake fluid in the rear lines would also have a bearing on the effectiveness of the brakes.
Is that correct?
cheers,
Anarki!
1990 Subaru Fiori,
1991 Fiat Niki, (For sale)
1971 Hillman Hunter
1991 Fiat Niki, (For sale)
1971 Hillman Hunter
As I said before, disk brake systems don't have a non-return valve because the disk pads are actually an interference fit against the rotor and if a non-return valve was used it would not allow the fluid to drain away and the brakes would stay locked on. I found this when fitting disks to a EH Holden.
Looking at the problem and reading the manual I note that the brakes have a 2 separate systems, one left front to right rear, the other right front to left rear.
If one of these circuits fails, say through leakage or a collapsed rubber, there is an extra distance to depress the brake pedal to operate brakes as it tries to make up for the faulty circuit.
It seems likely you have one faulty circuit.
To test this theory, drive at about 15k on a grass or sand/gravel surface, then jam the brakes on hard. The good circuit will lock up, so you know which circuit to look for faults in, if it is the rear wheel you only have to put a new brake kit in, if it is the master cylinder you will obviously have to put a kit through it. In view of the fact that the brakes have all done equal work and are most likely equal ages, if one fails most likely the others are only just behind it, so it would probably pay to put new kits in the rear and master and front disk cylinders.
The fact there is no visible leakage does not mean the cylinder is working, the rubbers may have seized inside or collapsed and the outside seal could be holding all the fluid in.
If the fluid is dirty it is well past it's use by date. When bleeding make sure you use enough fluid to completely replace the existing fluid as you don't know what brand it is and it may not be compatible with the new stuff.
Looking at the problem and reading the manual I note that the brakes have a 2 separate systems, one left front to right rear, the other right front to left rear.
If one of these circuits fails, say through leakage or a collapsed rubber, there is an extra distance to depress the brake pedal to operate brakes as it tries to make up for the faulty circuit.
It seems likely you have one faulty circuit.
To test this theory, drive at about 15k on a grass or sand/gravel surface, then jam the brakes on hard. The good circuit will lock up, so you know which circuit to look for faults in, if it is the rear wheel you only have to put a new brake kit in, if it is the master cylinder you will obviously have to put a kit through it. In view of the fact that the brakes have all done equal work and are most likely equal ages, if one fails most likely the others are only just behind it, so it would probably pay to put new kits in the rear and master and front disk cylinders.
The fact there is no visible leakage does not mean the cylinder is working, the rubbers may have seized inside or collapsed and the outside seal could be holding all the fluid in.
If the fluid is dirty it is well past it's use by date. When bleeding make sure you use enough fluid to completely replace the existing fluid as you don't know what brand it is and it may not be compatible with the new stuff.
Also check the proportion valves, those things are a bastard if they're not working properly and will cause screwy results all over the shop.
F8B EFI turbo - Three pots and a snail.
Have you priced a set for an MB? Holy jebus there's no way I'd be replacing them unless they were shot!
I pull mine apart for a clean and inspection at each pad change, I reckon thats enough.
I pull mine apart for a clean and inspection at each pad change, I reckon thats enough.
F8B EFI turbo - Three pots and a snail.