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Post by Gianni on Jul 27, 2006 4:54:23 GMT
my handbrake is reluctant to release I have to engage gear and move off against it to make it release which it does with a bang and a shudder the coupe has not been in use for 4 years and I am hoping it is a 'use' fix only should it be lubricated or adjusted somewhere? is there a known issue withthe handbrake? Gianni
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Post by johnwp5bcoupe on Jul 27, 2006 5:40:34 GMT
It's a case of clean and check/lube all the pivots and linkages from front to back could be the mechanism in the rear brake cylinders?? I would do a good refurbish! Good Luck
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Post by Phil Nottingham on Jul 27, 2006 15:55:08 GMT
The rear cylinders should be free enough enough slide on the backplates
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Post by Gianni on Jul 28, 2006 5:31:17 GMT
the sliding cylinders sounds like the P3 rod operated rear brakes which have a mechanism which slides on the backplates
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Post by johnwp5bcoupe on Jul 28, 2006 6:20:09 GMT
It will more likely the two sliding tappets or the roller which are rusted to the dust cover plate all of which are part of the brake cylinder and as Phil says the cylinders should be able to slide on the backplate.
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Post by Phil Nottingham on Jul 28, 2006 17:55:04 GMT
Being Girling the hanbrake mechanism and expanders are like the P3 and p2 and mnay other British cars of the 30-50's fitted with mechanical rod brakes
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Post by harvey on Jul 28, 2006 19:10:21 GMT
Why do the cylinders need to slide on the backplate?
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Post by Phil Nottingham on Jul 28, 2006 19:40:37 GMT
Essential on Girling brakes as it allows the shoes to centralise, give equal effort to each shoe and reduces pedal travel
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Post by johnwp5bcoupe on Jul 28, 2006 19:43:59 GMT
To keep the shoes in a central position if you lock the wheel cylinder it will cause uneven pressure on one shoe making the braking less efficient also uneven wear on the shoes. That's how I think it works perhaps another member has a better description.
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Post by harvey on Jul 28, 2006 19:55:41 GMT
This is P5b you're talking about, the ones with dual acting cylinders? Any dual acting cylinder gives equal effort to each piston without the need for the cylinder itself to slide. Im sorry boys but I think you're wrong on this one
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Post by johnwp5bcoupe on Jul 28, 2006 20:53:22 GMT
I may be wrong Harvey I agree they are dual action but I know when I stripped my axle down the cylinders moved and were fitted with a spring of 2 turns "NOT" a spring washer and held with a nylock if they were fitted fixed why not a spring washer and tightened in the normal manner! I am not saying I am total correct and always willing to learn even at my tender age
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Post by harvey on Jul 28, 2006 21:09:55 GMT
Same here, all we want here is the correct info, if I'm wrong I'm quite prepared to admit it, all I know is dual acting cyls dont NEED to slide and sliding cyls normally have some provision for flexibility in the brake pipe so any bacwards & forwards movement doesn't cause a fracture over time. Perhaps rather than using the word "sliding" a more appropriate description might be "floating". That just seems to imply less movement. I await your reply with interest.
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Post by Phil Nottingham on Jul 28, 2006 21:36:13 GMT
If you use Search you will find this same topic crops up over and over again both on this forum and the old one.
Sliding or floating Girling brakes must be able to centralise otherwise they cannot be fully adjusted to give minimum pedal travel. This even more so with the large bore hydraulic cylinders as opposed to rod operated brakes, they may be dual acting but if they are not exactly centralised often two pushes on the pedal will be needed to get a decent brake.
The washer are not ordinary spring washers either and the days before Nylocs used Castle nuts and cotter pins.
Also refer to the workshop manual
These brakes got a bad name because mechanics used to overtighten the nuts or fail to ensure they floated.
My P2 brakes are as good as many hydraulic types as are my P5's (both footbrake or handbrake) This maintenance issue was the reason that Rover did not use the same system on Land Rovers
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Post by harvey on Jul 28, 2006 21:45:21 GMT
There we are then, problem solved from now on we refer to them as floating rather than sliding cylinders as you have in your last post. An interesting exchange of views which I hope we can agree was a score draw.
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Post by Phil Nottingham on Jul 28, 2006 21:53:52 GMT
Do yours float? They should be just about moveable by hand with the drum off and the shoes fitted. They should not be so loose as to be able to tip/wobble.
As the linings wear unevenly because of the design this also helps reduce the effect but its a common cause of the handbrake sticking on after standing for a long time even with the brake off - the P4 uses the same set up
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Deleted
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Post by Deleted on Jul 28, 2006 22:11:51 GMT
"Floating" is term not understood by many although it is the more correct term - the cylinders do actually slide, the holes are slotted to allow this - no strain is likely on the pipes as the slots are not very wide and the cylinders/expanders do not move much or very often which is why they so readily seize up
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Post by johnwp5bcoupe on Jul 29, 2006 6:10:42 GMT
Another pennies worth floating in my opinion would mean not fixed as in the dictionary "suspended freely" Sliding means being able to "move across a surface" I think I prefere mine "nutted" "sprung" and "sliding" --------------------------------------------------------------------------------- I just read the 3lt workshop manual it says :- Leave the wheel cylinder fixing nuts one turn slack so that the cylinders are free to float on the anchor plate so the P5b was fitted with springs and the P5 wasn't seems that way.
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Post by Deleted on Jul 29, 2006 8:08:57 GMT
All these cylinders use double spring washers although they are different part numbers on 3 litres as the cylinder has three fixing studs not 2
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Post by johnwp5bcoupe on Jul 29, 2006 11:41:56 GMT
There must have been a transition period then because my parts book is for a P5 3Ltr and it shows only a two stud fixing?
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Post by Gianni on Aug 15, 2006 21:31:38 GMT
finally got the rear brakes apart. Nothing was floating, all was solid (though corrosion and dirt mainly), but the main finding was a detached lining which explains the faulty handbrake and the long pedal travel. Will reassamble tomorrow and leave the cylinders floating as I have the double spring washers. Bit worried about getting the springs back in though, they seem very strong and were hell to remove. Should the handbrake mechanism on the back of the cylinders be lubricated?
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Post by Phil Nottingham on Aug 15, 2006 21:47:25 GMT
The springs are not too bad to get on Girling made a special tool which avoids overstretching them but it can be done without using a long sturdy screw driver.
Copaslip antiseize type grease is best for the roller tappets and also in between the cylinder and brake anchor plate as this helps prevent corrosion. The cylinders should easily slide but not allowed so loose that they actually rock side to side. Make sure the shoes are put the right way round with the end with the flat on it resting on the handbrake tappets. Many garages fir them opposite and tighten up the cylinder fixing screws. I hope you took note of which springs go into which holes as again there is only one right way but they will fit in various combinations!
When properly set up the P5 hand brake is very efficient and way in excess of the legal minimum standard.
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Post by Gianni on Aug 16, 2006 4:01:20 GMT
thanks for that have been trying to source a tool and found one on ebay but not through local tool suppliers. Will try and source that sort of grease. took photos and studied the parts book so hope I can get them back in the right way. I am hoping the handbrake will work well once everything is back together.
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Post by Gianni on Aug 17, 2006 11:50:27 GMT
Got them back together ok. Everything looked fine. Test run started off well but then the car came to a stop when I changed gears. the brakes were locked on solid. Front and back! Bled a little to release them and got home using the handbrake mostly but did forget at one point and the brakes seized up again and gave great smoke at the front wheels. Now the brake pedal solidifies to a rock after a few pumps (all wheels locked) and I think the booster is the problem but , d**n it, it is a brand new one and was working fine before. anyone had something like this before?
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Post by Phil Nottingham on Aug 17, 2006 16:18:26 GMT
Yes - the air piston can stick after periods of disuse. It may free off if you press brake down hard several times and starting the engine without releasing it. Its under the White plastic body.
Alternatively a flexo hose could be collapsing or the master cylinder free travel on the pedal is insufficient
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Post by lagain on Aug 17, 2006 21:09:00 GMT
Yes they should be able to slide. All the instructions are in the manual. I believe in greasing every thing, just wipe the back of the cylinder with a tiny amount on your finger, and any other moving parts. Use ONLY Mechanical Brake Grease, which is green and available from Lucas. (PFG101) Never get it anywhere near linings .
I posted this before I realised there was a page 2 ;D
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