Brake Calliper binding on one wheel. Page 1 / 2

nzoomed, Mar 8, 11:47pm
My left front brake Calliper has started binding only afer a couple of days after replacing my girling powerstop brake servo, i stripped down the Calliper and cleaned it up, everything seems OK, a little bit of pitting on the pistons has started, but was past the seal and was not affecting their movement, the pistons move up and down freely enough, what could be causing this! Still doing the same thing after putting it all back. The brake hoses are OK and no blockages, very fustrating!

toyboy3, Mar 8, 11:48pm
improve the pedal free play

rod525, Mar 8, 11:57pm
That would affect every braked wheel, not just the l/f.

nzoomed, Mar 9, 12:15am
i did all that, made no difference, yep it was binding all right, car was starting to struggle and was smoking at the wheel, brake pedal was hard and smelt bad, the longer i drove the more it was binding.
The only way i got home was disconnecting the vacuum hose to the servo.
The brake was still binding after applying the brakes, but then would come right shortly after, however its still binding alot of the time now, even after a strip down.

nzoomed, Mar 9, 12:54am
all pads worn evenly, no problems with brakes prior to the diaphragm bursting on the servo and having to be reconditioned.
I lubricated the pads and pins with calliper grease, which didnt really make any difference.
I have not had to replace the pads, they are not too old and still have alot of life left.

nzoomed, Mar 9, 2:38am
i have just taken it for a drive, and now found its not just one wheel.
Both sides are doing it, and possibly the rear also, stumps me why only one wheel was smoking last week though, perhaps the other side was binding, but not just as bad!
Either way, the guy who rebuilt the servo told me to check the master cylinder, if thats the problem ill soon find out, otherwise it will have to be the servo.

mrfxit, Mar 9, 2:58am
AArrhhh
Master cyl thrust rod set to long.
Adjust for a bit more free play
You should be able to feel the peddle touching the master cyl rod by pushing very slightly on the brake peddle.
If theres no gap between the peddle & the rod, the brakes will always be on slightly
Push the peddle & you should "feel" the peddle tapping the rod.

sr2, Mar 9, 3:04am
A modern Hydrovac booster is vacuum suspended in the rest position; a vacuum leak or blockage will not cause the booster to activate. It will only activate if the reaction disk is compressed, this can happen when the input shaft (connected to the pedal) is incorrectly adjusted or occasionally if there is insufficient clearance on the output shaft (sometimes a result of a gasket or spacer [if fitted] being left out). I??

nzoomed, Mar 9, 3:11am
ive just puled off the master Cyl, there is enough play on the pedal as not to be putting pressure on the shaft, will let you what i find, if its OK when pulled apart, i know its got to be the servo unit at fault.

mrfxit, Mar 9, 3:57am
Looks like it's between me & biker

Possibly closer to bikers idea but could swing either way.

Noted: booster servo recently overhauled . possible internal fault!

mrfxit, Mar 9, 3:58am
Could be all 4 wheels dragging but due to the nature of brakes, it's the front that have the most effect with the back simply being dragged along.

les6, Mar 9, 4:02am
had a similar problem lately after reconditioning of my servo,only one wheel though and it turned out that alot of crap had been dislodged and partially blocked the hose at a point where the inside of the hose had started to deteriorate.

nzoomed, Mar 9, 5:36am
the hoses are OK in my case, but i know what you mean, i have seen it lots on old brake hoses.

intrade, Mar 9, 5:58am
well remove the hose and see if you can blow thru it you wont see internal collaps on a brake hose. meaning it lets fluid travel only one way .

supernova2, Mar 9, 6:44am
Had a similar problem years ago with an Austin Maxi.Brakes would simply apply themselves till total lock up.Repair kit to Master Cyl and problem fixed.Couldnt see anythink wrong with old seals etc but the kit fixed the problem.Think it cost all of about $5 too

bcbuilding, Mar 9, 7:00am
Thats what I should have done.Has the R/R drum on my torana catch fire outside Riccarton Mall one evening, and theL/R pads fell out when I pulled over to deal with the other.It had new pads and Master Cyl overhaul at Midas two days earlier.Leave it to the professionals my f-king ar$e.

intrade, Mar 9, 7:05am
midas-well forget it.

intrade, Mar 9, 7:06am
i just done a corolla master cilinderwhole new unit with fluid bowl and fluid level sender. from partsmaster 80$

nzoomed, Mar 9, 8:21am
will keep you posted tomorrow when i put it all back together, fingers crossed, i'll check the hoses, but i doubt they are at fault.

sr2, Mar 9, 8:59am
Hold on guys I think we may all be barking up the wrong tree! I??

nzoomed, Mar 9, 9:50am
i will do that if i dont get anywhere, thanks for that info, the brake shop suggested i do that too if i continue to have problems.

I dont think a girling hydrovac booster is the same thing as a girling powerstop though, i think the powerstop is closer to the PBR VH40 in power.

mk3zephyr, Mar 9, 10:45am
Ah so it had, had the "Midas Touch" huh, A few years ago this chick i knew bought her car around for me to have a look at it, she had just had taken it to midas for new front brake pads and when applying the brakes there was a horrible metallic sound from the right front, Jacked it up, whipped the wheel off and there was only the outer pad in the caliper, the inner was non existant, how the piston never popped out beats me, Anyway i took her down to Midas and had it out with them, they reckoned the pad must have fallen out on the road. How the heck would a pad just fall out!.To cut a long story short we got the so called Tech who did her car to search through the bin to find the box the pads were in and sure enough there was a brand new pad sitting in there, Got said pad, got her a refund and made them pay for another 2nd hand rotor from a wrecker as the one on her car was rooted. I also remember one of those places midas or pitstop years ago didnt do up the calipers on an old couples car, they went on a long trip and were killed near karapiro when the calipers literally fell off the car, Couldnt stop, no brakes, cant remember what the outcome was tho, think the "tech" got done for 2 counts of manslaughter, was in the early 90's

sr2, Mar 9, 8:07pm
Girling 808 Powerstop??

nzoomed, Mar 9, 8:41pm
ok thats interesting info, i always thought that the VH40 had the same or similar power to my powerstop, a vh44 would not give me enough braking power in my car, the aussies put VH40 boosters in them from the factory (austin 1800) VH40 boosters are supposed to be for cars with front disc or full disc brakes and the VH44 for drum brakes only, but i guess it depends on the car itself. i am aware that both the powerstop and PBR boosters both had a range of bore sizes, the smaller bore sizes actually had greater braking pressure, or so im told anyway.

sr2, Mar 9, 9:07pm
It gets confusing; the different models have different output gains, cracking pressures, fluid displacement and simple or compound type control valves. You are basically correct in your assumption although the.75 inch VH44 was used on the front disc??

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