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I understand that locking the brakes is definitely not a desireable condition if you are trying to brake in real life however I find it useful in a low speed test to determine if the brakes are working to their full potential.
I think that on vehicle with the poor brakes that the brakes are unable to even get close to the maximum braking condition.
Is it possible that the pad/lining material is too hard or something like that?
I don't like that not stopping fast enough feeling :eek:
My 85 County was terrible until I fitted a 93 defender disc brake rear end, brakes are great now and no need to change the master cylinder. Another point is to make sure your discs/drums are still within spec.
Maggsie
It is possible that you have too hard pads/lining material. However, it occurs to me that there is another possible variable - the amount of vacuum you have for the booster. The vacuum pump (assuming you have a diesel) could be worn, or with either petrol or diesel a leaky or partly blocked vacuum line would have a similar effect, as will having the vent on the booster partly blocked, the booster itself leaky or with a leaky diaphragm.Quote:
Originally Posted by wovenrovings
John
as john said....if you have soft compound pads in the front...they will need less pressure to work......
they may well be working before the back brakes get enough pressure to do much......
they (front pads) will wear out quicker but will work great......
have you adjusted the rear drum brakes correctly.......?
if you pump the pedal and it comes up and works better on the second pump....then you need to adjust the rear brakes......
if they are adjusted......try this to see if it makes any difference......
with the cap off the brake fluid reservoir......
loosen each bleed nipple (only one at a time though) one or two turns......watch and see if and bubbles come out......
you should have a slow drip of steady fluid come out the nipple....without any bubbles.....
just check them all and make sure......this is assuming you have already bled the brakes......this step seems to remove any air
that may still be trapped in the cylinders/calipers after bleeding.....
I had a vehicle that had a lever arrangement on the rear suspension which automatically adjusted the rear brake bias. I can't remember if it was my old Seventies Transit van.Quote:
Originally Posted by JDNSW
My '84 County had appalling brakes (in comparison to my P38A).
Ron
I have noticed this on current Landcruiser utes (actually on cab/chassis where you can see it without crawling underneath).Quote:
Originally Posted by p38arover
When you say your County had appalling brakes - in what way? Pedal pressure? Uneven braking? Fade? Pedal free movement?
Holden One tonners had an anti skid arrangement like this.Quote:
Originally Posted by p38arover
None of the above. It stopped straight, pedal pressures were good, fade was never tested, pedal free movement could be taken out with rear shoe adjustment. It just didn't stop as well as the P38A which is a lot heavier. I accptd that as just being more modern and powerful brakesQuote:
Originally Posted by JDNSW
But it wasn't until one jumped straight out of it into a Defender that one noticed that the Defender had far better brakes. The difference was so marked that it was one of the reasons I considered replacing the rear end with Defender rear.
It was also one of the reasons I sold the County.
I weighed up what I'd have to spend to do that, add working aircon, get a split rear seat, etc., that I decided I might as well buy a later Defender. (There were other reasons - I have a P38A, I might as well spend the money on improving it for touring, etc.).
Ron (who misses the County. Should never have sold it. :( )
If it was none of the above I am at a loss to understand in what way the brakes were lacking - what do you mean by it didn't stop as well? Was it because you had to push the pedal harder for the same deceleration? (covered by pedal pressure) Was it because the braking was not progressive? This is something I did not cover - for example running out of vacuum could result in the braking effect being less than expected for hard applications (this could also result from fading of the rear brakes on hard applications as the self energising effect of the leading shoe decreases).Quote:
Originally Posted by p38arover
What do you mean by powerful when talking about brakes if you don't mean either pedal pressure or fade resistance?
John
I'm thinking the other variable is when there's less friction with the road than on the brakes - the deceleration required to lock the wheels which also varies on tyre compund, road surface etc.Quote:
Originally Posted by JDNSW
But re pedal pressure - For a couple of months I drove with the vacuum booster disabled on my Stage 1 (drums all round). I knew the brakes would retard just as well just with more pressure - a lot more pressure. Even now the pressure required is force from the thigh not force from the ankle and I sometimes bring my Hyundai buzz-box to a screeching hault forgetting it's not so heavy. I find County brakes quite impressive with pedal pressure(haven't tried fade yet, or if I can get the rears to lock).
Steve