thor64
Rover Fanatic
Posts: 138
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Post by thor64 on Mar 3, 2022 20:16:26 GMT
I hope this post is of interest to 3 litre owners. My 64 Coupe has only a few jobs left and changing the brake fluid is one. I spent many a happy hour/ week rebuilding the front callipers; especially a jammed in bleed nipple but onto the cylinders on the rear. Trust Rover to come up with two different ways to block off the brake fluid passage to the nipple. The ingenious method on the rear cylinders is to use a ball baring between the hole and the bleed nipple. Screwing down the nipple holds the ball baring in the hole. I have never come across this mechanism before ( see photos). I was able to disassemble the cylinder on the passenger side to be rebuild it and using a magnet out came the ball baring from the cavity in the back. All good and ready to go back. On to the drivers side and the same procedure was used with the magnet. The ball baring would not come out. It was jammed good and solid. I surmise a previous owner, heavy handed, had tightened up the bleed nipple so tight it jammed the ball baring. I rebuilt the cylinder and tried using the pedal hydraulic system to push the ball baring out but to no avail, it was really jammed. So I walked away and took advice. One tip was to use vinegar down the hole to help loosen any dirt trapping the ball baring, which I did. Now for the surgery. I worked out that I could make a pin which could be introduced into the hole in the cylinder and then from behind force out the ball baring. Measuring the diameter of the cylinder I knew how long to make the pin and from the passenger side cylinder I was able to determine the thickness of the pin. It happens that the shaft from a pop rivet was just right. Then using a magnet I was able to feed the pin up in the cylinder and introduce it to the passage that went to ball baring. Prising on the pin, inside the cylinder, with a screwdriver I was able to move the pin in and out popped the ball baring. I know that you can use the bleed nipple from the front calliper on the back cylinders so doing away with the need of the ball baring which I will employ. Attachments:
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Post by Phil Nottingham on Mar 4, 2022 10:11:49 GMT
Those cylinders were not a success and overtightening can split the cylinder. Standard bleed nipples fitted often leak as well. They are now obsolete
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thor64
Rover Fanatic
Posts: 138
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Post by thor64 on Mar 20, 2022 13:37:46 GMT
Hi, I am having trouble with how the brake peddle should feel. Ive been reading the posts/ threads on brakes and it is described as firm. I press my peddle and there is firm resistance which stops the car but I can, if I try push the peddle to the floor. No leeks I can find. Wondering if it is this fluid bypassing the servo seal problem? My car has the Lockheed conversion which I have not touched yet or has it still air in the system?
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Post by Phil Nottingham on Mar 20, 2022 15:44:53 GMT
No way should the pedal go to the floor - air must be in the system. Does the servo outlet point upwards slightly?
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Post by lagain on Mar 20, 2022 16:51:00 GMT
I replaced everything rubber in the brake system over the winter. I had a litre of fluid on the shelf and another new litre. Rightly or wrongly I used the older litre to get the air out of the system by putting it round several times (observing good hygene !). Eventually the pedal had about an inch or so of travel and was very firm. I then chased the old fluid out with the new and am very pleased with the result. The brakes on the P5 and b are difficult to bleed and it probably takes 3 or more litres, which is why it is best to replace everthing at the same time, including flexible hoses. I find the rear cylinders more difficult to beed than the calipers.
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thor64
Rover Fanatic
Posts: 138
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Post by thor64 on Mar 20, 2022 19:47:50 GMT
Hi, I would say I have just about there in the replacement business. The master cylinder and servo as yet untouched. I agree you can't take chances with something as heavy as a Sherman tank. Though I have heard Rolls-Royce's have some play on their brake pedal. I will have to go through them again paying particular attention to the rear. The Mrs loves her visits to my shed where her calf muscles have a workout. Being new to the workings of the Lockheed servo. I have attached photos to help with the position of the outlet point. Attachments:
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Post by lagain on Mar 21, 2022 16:54:34 GMT
I would suggest that you replace the seals in the master cylinder and the servo if you do not know when they were last done and the flexible hoses. The problem is that the new brake fluid can cause old seals to fail and then you are back to square one with the brakes.
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thor64
Rover Fanatic
Posts: 138
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Post by thor64 on Mar 21, 2022 19:33:39 GMT
Yes I do think it is time to do the seals. I think that one of the threads suggested the servo can be serviced without having to bleed the system or do you have to take the unit out?. I wondered if you had any advice?
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Post by MK IA Norway Viking on Mar 21, 2022 20:09:13 GMT
Good evening,
I have the old servo for the 3-litre MK IA and cannot say much about the Lockheed unit. To determine if you have air in the system leave the car sitting overnight and then start pumping the brake pedal noting how far it goes in on the first pump and if the travel is changing progressively with each pump. If the travel becomes shorter and shorter with each pump there will be air in the system - the pedal will travel less and less as the air become compressed.
For bleeding you should start with the caliper / brakecylinder that is the CLOSEST to the servo unit. There is a device available at most auto-hardware shops consisting of a transparent plastic hose that fits the bleeding nipple on one end and have a one-way valve on the other. Using this enable one person to bleed hte brakes without having to close and open the bleed-nipple for each pump of the pedal. You will naturally end the job with the nipple that is the furthest away from the servo.
I suspected at some point the master cylinder on my car to be faulty, and bought two so one could be spare.
Turned out, the culprit was the servo, with brake fluid slipping from the inlet chamber on the servo (where the pipe from the master cylinder connects) over the seal in the vacuum cylinder.
From there the fluid was sucked into the engine and out the exhaust by action of the vacuum induced from the inlet manifold.
When I took off the servo, and released the large end-cover, brake fluid was pouring out.
There is a service kit available to rectify same.
Good luck in sorting your problem.
Kindest regards, Christopher Oslo Norway
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Post by lagain on Mar 22, 2022 16:55:25 GMT
Yes I do think it is time to do the seals. I think that one of the threads suggested the servo can be serviced without having to bleed the system or do you have to take the unit out?. I wondered if you had any advice? Unfortunately the servo does have to come out and then be taken apart. If the servo is the same as fitted to the P5b the procedure is in the workshop manual and it is fairly straight forward. Still assuming that it is the same servo Wadhams has a choice of 2 kits for overhaul or even a replacement.
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Post by Phil Nottingham on Mar 22, 2022 18:32:19 GMT
NO, it cannot be serviced in-situ.
It is not worth the effort to service the unreliable Girling servo. It is better to fit the P5B Type 7 servo. Wadhams does the kit. Removal of the inlet manifold is required to do a proper job
SEARCH will reveal more tips
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thor64
Rover Fanatic
Posts: 138
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Post by thor64 on Mar 22, 2022 20:30:16 GMT
Hi and thanks for the useful advise. I posted two photos of my Lockheed servo- are the photos not coming up? I gather it is the same as the one on the V8 and the install looks very professional , especially how it fits to the intake manifold. I have seen the one way valve mechanism in use. I have a vacuum system which draws the air and fluid into a canister. I don't seem to be getting any loss of fluid in the reservoir, so I am hoping it is not the servo filling up.
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Post by MK IA Norway Viking on Mar 22, 2022 21:47:08 GMT
Good evening - you have to assess whether there is air in the system before taking any further action.
To determine if you have air in the system leave the car sitting overnight and then start pumping the brake pedal noting how far it goes in on the first pump and if the travel is changing progressively with each pump.
If the travel becomes shorter and shorter with each pump there will be air in the system - the pedal will travel less and less as the air become compressed.
If the pedal travel is constant there is no air in the system and you can go ahead with replacing / servicing the servo unit.
My impression is that it is rarely the master cylinder which is the culprit.
Good luck !
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thor64
Rover Fanatic
Posts: 138
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Post by thor64 on Mar 23, 2022 10:30:45 GMT
Like you say the peddle distance does get shorter as you pump it. My job for today is back to jacking it up, taking the wheel off and removing any air, in the brake system, not the tyre. Another step to getting it on the road. It has now decided to evacuate coolant via the radiator cap. Another spanner in the works.
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Post by MK IA Norway Viking on Mar 23, 2022 12:48:49 GMT
Good to hear that the distance your brake pedal is travelling is reduced with the amounts of pumping it. Bleeding the system should go fine. Make sure you top up the brake fluid reservoir so air does not enter the system while bleeding it...
Keep an eye on the brake fluid level for the first few trips you make with the car, to see if it remains constant or require topping up. If topping up is needed there will be additional issues, which are likely to be the servo unit.
Best wishes for a successful brake-job !
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