Jump to content


Front brakes dragging WB caliper

Started by _GTRXU1Rooster_ , Mar 10 2011 09:22 PM

  • Please log in to reply
65 replies to this topic

#26 S pack

S pack

    Scrivet Counter

  • Members
  • PipPipPipPipPipPipPip
  • 15,566 posts
  • Name:Dave
  • Location:Luggage Point
  • Car:73 LJ
  • Joined: 25-January 10

Posted 03 April 2011 - 10:33 AM

Alrighty,

Yesterday arvo mate came round with his HX Kingswood, with disc/drum setup, chucked his master on to start with, it was the back to front facing one but the front hose goes to the front ofthe proportional valve same as the way mine was, fitted it up same as it was on his car and same problem brakes holding on. then chucked his proportional valve on and once again nothing changed.

So this tells me that

Master not the problem
Proportioning Valve not the problem
Calipers not the problem

So could it be the Rubber hoses or even the metal hoses? Like the hoses collapsing under vacuum, if it were them I would have thought that days later the fluid would have bipassed and returned to normal?

Any ideas?

Clay


G/day Clay
Geez mate your not having much luck with that.

Well if it's not the master cyl, prop valve or calipers then it doesn't leave much else than an obstruction in the brake pipe between the master and the prop valve (if both calipers are dragging, and I would suspect if there is an obstruction you would also have problems bleeding the brakes).

Rubber hoses to calipers, mmmmmmmmm, change them anyway if they are old and you think they are suspect.
Only really leaves the brake booster adjustments.
Either the length of the pushrod into the master is too long or you have the pushrod from the brake pedal to the relay lever assy adjusted incorrectly.

Just my thoughts.

Cheers
Dave

#27 _GTRXU1Rooster_

_GTRXU1Rooster_
  • Guests

Posted 03 April 2011 - 10:58 AM

G/day Clay
Geez mate your not having much luck with that.

Well if it's not the master cyl, prop valve or calipers then it doesn't leave much else than an obstruction in the brake pipe between the master and the prop valve (if both calipers are dragging, and I would suspect if there is an obstruction you would also have problems bleeding the brakes).

Rubber hoses to calipers, mmmmmmmmm, change them anyway if they are old and you think they are suspect.
Only really leaves the brake booster adjustments.
Either the length of the pushrod into the master is too long or you have the pushrod from the brake pedal to the relay lever assy adjusted incorrectly.

Just my thoughts.

Cheers
Dave




Its not the booster, after bleeding up the brakes and it had the drag on, I disconnected the master away clear of the Brake Booster, clear of the push rod out the front of it and they stayed on.

The Brake hoses are fairly new, they are a few years old but have never really been used, they were fitted up but havent seen any street use. So I have no idea what they are like but considering I have had the Booster, Master, Calipers all rebuilt so nothing really left to rebuild.

Occasionally bleeding up the front brakes can take a bit sometimes they are fine, but once there is a bit of pedal they feel really good....

any other dieas?

Clay




#28 S pack

S pack

    Scrivet Counter

  • Members
  • PipPipPipPipPipPipPip
  • 15,566 posts
  • Name:Dave
  • Location:Luggage Point
  • Car:73 LJ
  • Joined: 25-January 10

Posted 03 April 2011 - 11:24 AM

Its not the booster, after bleeding up the brakes and it had the drag on, I disconnected the master away clear of the Brake Booster, clear of the push rod out the front of it and they stayed on.

The Brake hoses are fairly new, they are a few years old but have never really been used, they were fitted up but havent seen any street use. So I have no idea what they are like but considering I have had the Booster, Master, Calipers all rebuilt so nothing really left to rebuild.

Occasionally bleeding up the front brakes can take a bit sometimes they are fine, but once there is a bit of pedal they feel really good....

any other dieas?

Clay


Running out of ideas fast mate.

Can only say that I had a WB 1tonner and when I put new DBA Gold front discs and new Ferrodo pads on her the calipers were hard to get over the discs, like the new pads were too thick. The front wheels were harder than normal to turn by hand but after a few K's the pads wore in and all was fine.
Have also struck the same sort of issue with our VS commy.
Other than that, I'm stumped.

#29 _GTRXU1Rooster_

_GTRXU1Rooster_
  • Guests

Posted 03 April 2011 - 11:31 AM

yeah they are a bit tight to get over initially, when I ran it down the strip and they were dragging on, they glazed over, so I hit them with a sander to get the glaze off them and now there is a bit more room but still reasonably tight but with a screw driver to pull them back there is plenty of free play..... so yeah I am struggling too. my mechanic mate too is stumped as he has been assisting me but is completely out of ideas too

Clay

#30 dattoman

dattoman

    Do I feel lucky? Well, do ya, punk?

  • Administrators
  • PipPipPipPipPipPipPip
  • 16,473 posts
  • Name:Neil
  • Location:Perth Western Australia
  • Car:LX SS , 76 Cadillac , 3 x dattos
  • Joined: 04-February 07

Posted 03 April 2011 - 12:08 PM

Rekit the calipers

And replace the hoses while your at it

#31 _GTRXU1Rooster_

_GTRXU1Rooster_
  • Guests

Posted 03 April 2011 - 12:12 PM

Datto,

Already put a kit thru the calipers, and then went and got them tested by a brake shop and they said that there was nothing wrong with them and they gave them a clean out too.

I will get new hoses then next and give that a crack, and then if that fails then replace all the metal brake hoses too and then???? burn the lot

Clay

#32 dattoman

dattoman

    Do I feel lucky? Well, do ya, punk?

  • Administrators
  • PipPipPipPipPipPipPip
  • 16,473 posts
  • Name:Neil
  • Location:Perth Western Australia
  • Car:LX SS , 76 Cadillac , 3 x dattos
  • Joined: 04-February 07

Posted 03 April 2011 - 12:17 PM

Replace the seals in the calipers.... if you can't push the pistons back with your fingers they are too tight.... don't need screwdrivers

They might have the wrong seals in them

Had same issue with a GTHO during the week
Wrong seals in kit
Right diameter... but too wide

#33 _Quagmire_

_Quagmire_
  • Guests

Posted 03 April 2011 - 12:25 PM

try bleeding it again
and free your pistons while your there
with a clamp
just in case
you checked the check valve as datto suggested?


sentance two
said it over a month ago would have saved you a lot of hassles :)

#34 _GTRXU1Rooster_

_GTRXU1Rooster_
  • Guests

Posted 03 April 2011 - 12:25 PM

I will take them off again and see if they will slide in and out with just fingers then.

will get back on this arvo with results

Cheers

Clay

#35 _GTRXU1Rooster_

_GTRXU1Rooster_
  • Guests

Posted 03 April 2011 - 02:13 PM

Replace the seals in the calipers.... if you can't push the pistons back with your fingers they are too tight.... don't need screwdrivers

They might have the wrong seals in them

Had same issue with a GTHO during the week
Wrong seals in kit
Right diameter... but too wide


well I definately cant slide them back with my fingers thats for sure, I previously had the cleaned up, had a brand new kit put thru them by a mechanic, then after this I was still having the issue, so I took a caliper to the brake shop, and they tested it and said it was working fine.... they are suposed to be experts so when they say theres nothing wrong with it, you generally take their word????

I will take them into a different shop then and get them to put another kit thru it too and see if that works? other than that I am running out of ideas.....

which would I be better of with though, WB Calipers or VL Calipers? I thought the VL were supposed to be better but have a smaller piston making them not as good right

Clay

#36 dattoman

dattoman

    Do I feel lucky? Well, do ya, punk?

  • Administrators
  • PipPipPipPipPipPipPip
  • 16,473 posts
  • Name:Neil
  • Location:Perth Western Australia
  • Car:LX SS , 76 Cadillac , 3 x dattos
  • Joined: 04-February 07

Posted 03 April 2011 - 02:48 PM

They also don't fit


I'm not saying the calipers are at fault... but... you have to try something.. and at the cost of kits its worth it

Pics of calipers ?

#37 _GTRXU1Rooster_

_GTRXU1Rooster_
  • Guests

Posted 03 April 2011 - 02:54 PM

They also don't fit


I'm not saying the calipers are at fault... but... you have to try something.. and at the cost of kits its worth it

Pics of calipers ?




the VL Calipers dont fit? bugger as I have a set in good nick here too

I will get some pics and post them up too

Clay

#38 _Ozzie Picker_

_Ozzie Picker_
  • Guests

Posted 03 April 2011 - 03:13 PM

i,m still thinking fexable hoses,lets fluid past under pressure and not returning,as i said earlier a friend had the same problem,so this maybe at fault,good luck mate,its a real head frock.

#39 _GTRXU1Rooster_

_GTRXU1Rooster_
  • Guests

Posted 03 April 2011 - 03:20 PM

well here are the pics of the caliper....

thinking its either this or the rubber flex hoses collapsing.... either way its annoying the crap outta me, its the think stopping me from racing it now too

Clay

Attached Files


#40 dattoman

dattoman

    Do I feel lucky? Well, do ya, punk?

  • Administrators
  • PipPipPipPipPipPipPip
  • 16,473 posts
  • Name:Neil
  • Location:Perth Western Australia
  • Car:LX SS , 76 Cadillac , 3 x dattos
  • Joined: 04-February 07

Posted 03 April 2011 - 03:43 PM

Where are the rubber pin sleeves that go over that pin ?
The one thats not full thickness all the way down ?

That fluid looks alittle.... undesirable... what are you using in it
And what do you lube the pistons with before sticking then back in ?

#41 _GTRXU1Rooster_

_GTRXU1Rooster_
  • Guests

Posted 03 April 2011 - 03:52 PM

Where are the rubber pin sleeves that go over that pin ?
The one thats not full thickness all the way down ?

That fluid looks alittle.... undesirable... what are you using in it
And what do you lube the pistons with before sticking then back in ?



the one that isnt full thickness all the way down, I broke that off taking it off last time it was off,
the rubber boots are on the other part of the caliper thats not shown

the fluid I am using is just standard DOT3 and its always clean new fluid that goes thru it....
the grease that was used was normal rubber grease after it was rekitted.

Clay

#42 _TorYoda_

_TorYoda_
  • Guests

Posted 04 April 2011 - 09:58 PM

Check that the bleed return hole in the master cylinder reservoir is not blocked. Take the lid off and have another person lightly press the pedal. You should see fluid movement in the reservoir each time they tap the pedal. If there is no fluid movement either the bleed hole is covered by the piston cup (meaning the pushrod is too long) or the hole may be blocked. I had exactly this same problem on a HR years ago and it turned out the rod was too long, blocking the return bleed hole. If this hole is blocked the fluid cannot return to the master cylinder as it expands from heat and will progressively lock the brakes until the car will not move. Knowing you have tried a different master on it my money is on the rod being too long. I have also had the old hose syndrome that Bathurst mentioned but it happened on the rear hose from the body to the diff. Good luck.

Edited by TorYoda, 04 April 2011 - 09:59 PM.

#43 _GTRXU1Rooster_

_GTRXU1Rooster_
  • Guests

Posted 06 April 2011 - 07:25 PM

Check that the bleed return hole in the master cylinder reservoir is not blocked. Take the lid off and have another person lightly press the pedal. You should see fluid movement in the reservoir each time they tap the pedal. If there is no fluid movement either the bleed hole is covered by the piston cup (meaning the pushrod is too long) or the hole may be blocked. I had exactly this same problem on a HR years ago and it turned out the rod was too long, blocking the return bleed hole. If this hole is blocked the fluid cannot return to the master cylinder as it expands from heat and will progressively lock the brakes until the car will not move. Knowing you have tried a different master on it my money is on the rod being too long. I have also had the old hose syndrome that Bathurst mentioned but it happened on the rear hose from the body to the diff. Good luck.


but disconnecting the master away from the booster would eleviate this issue then wouldnt it?

Clay

#44 dattoman

dattoman

    Do I feel lucky? Well, do ya, punk?

  • Administrators
  • PipPipPipPipPipPipPip
  • 16,473 posts
  • Name:Neil
  • Location:Perth Western Australia
  • Car:LX SS , 76 Cadillac , 3 x dattos
  • Joined: 04-February 07

Posted 06 April 2011 - 07:37 PM

Nope
If the hole is blocked it can't compensate

#45 _GTRXU1Rooster_

_GTRXU1Rooster_
  • Guests

Posted 06 April 2011 - 07:40 PM

Nope
If the hole is blocked it can't compensate


but the other master that was used on it was off a car that drove to my house so it cant be a master issue, and the master was then taken away from the booster so it cant be the rod going inot the back of it either then???

Clay

#46 dattoman

dattoman

    Do I feel lucky? Well, do ya, punk?

  • Administrators
  • PipPipPipPipPipPipPip
  • 16,473 posts
  • Name:Neil
  • Location:Perth Western Australia
  • Car:LX SS , 76 Cadillac , 3 x dattos
  • Joined: 04-February 07

Posted 06 April 2011 - 09:11 PM

Yep
I see your point
But I was just answering the question as posed... not specifically why your car is being a skirt wearer

#47 _GTRXU1Rooster_

_GTRXU1Rooster_
  • Guests

Posted 30 April 2011 - 08:06 PM

well I got the calipers completely rebuilt again with new pistons included this time, and brand new braided hoses and even new brake lines as well. now the passenger side is working and the drivers was workin fairly well but not brilliant. then started failing again. took them back in and after a long time with just the air compressor popping them in and out where they were working fine they then started jamming up.


Apparently the other side to the piston over 30 odd year has flexed or something and opened up slightly and allowed the pad to push on an angle and then the piston then can apparently turn slightly and bind up on the sleeveand not release back into the caliper????


now Dattoman is this a reasonable presumption? is there a cure to this? can it be sleeved or something? can the caliper be pressed back into shape?


Any ideas would be great,


Clay

#48 dattoman

dattoman

    Do I feel lucky? Well, do ya, punk?

  • Administrators
  • PipPipPipPipPipPipPip
  • 16,473 posts
  • Name:Neil
  • Location:Perth Western Australia
  • Car:LX SS , 76 Cadillac , 3 x dattos
  • Joined: 04-February 07

Posted 30 April 2011 - 09:59 PM

No
They can't be sleeved... or bent back to shape
The only way the caliper body can be bent... and yes I have seen this happen on WB... is if they have been seriously toasted enough to distort that thickness of aluminium... and that just doesn't happen easily.
If thats really happened... in the bin with them

However.... the piston only moves a poofteenth of an inch on each application
The piston is highly unlikey to cock off on an angle unless its fairly out of the bore
i.e very worn pads/discs

Shame you fitted braided lines... you can't clamp them to isolate the calipers anymore

#49 _GTRXU1Rooster_

_GTRXU1Rooster_
  • Guests

Posted 01 May 2011 - 07:25 PM

yeah the piston was getting a rub mark on the rear edge of the piston after it was jamming up a couple of times, only on 1 side

the caliper was working for a fair period and then it just kept failing and the piston is brand new too. the brake guru up here said that if the bit was bent then when the piston loads up it would try and twist the piston to the side slight and then when the pressure is released it was digging into the sleeve and binding up.

Atleast now I have found out its the caliper and nothing else now.... the passengers side is working a treat now.... now just gotta sort out the drivers, how I dont know yet, get a new one or change to HJ.

Clay

#50 _GTRXU1Rooster_

_GTRXU1Rooster_
  • Guests

Posted 07 June 2011 - 08:41 PM

Got another pair of calipers, kitted them again and the drivers side is jamming on as soon as they are applied. its only doing it on the one side of the car these days. with the wheel still off you can watch the calipers being applied and the still move a little and when applied you cant move the rotors at all, when released you can see some movement minimal as it is and the rotors are still on, but they can be turned but takes a fair amount off effort to do so though.

I took the old caliper to 2 different brake guys up here and they told me that the brake jamming on couldnt happen so they both tested it. with a piece of box pipe in it they couldnt get it to jam, as soo as they put the caliper slide on and fitted a pair of brake pads and another box pipe in it an inch thick to replicate the rotor it jammed up first time, and everytime since.... so that was the caliper isolated and it failed, now with another caliper on its doing the same thing.... I am completely lost

Clay
Back to Brakes, Wheels and Tyres


1 user(s) are reading this topic

0 members, 1 guests, 0 anonymous users

  1. GMH-Torana
  2. → Holden Tech
  3. → Brakes, Wheels and Tyres
  4. Privacy Policy
  5. The Rules! ·