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Post by mark21 on Oct 8, 2007 17:54:41 GMT
hi there just require some information about the handbrake. i have adjusted all the metal rod etc by the workshop manual (i am happy with ) but i find the handbrake cable to long(when handbrake pushed in loads of slack and when pulled out the handbrake traveled almost out of the handbrake housing be for brake lock up ,i am thinking of cutting a few inches of the cable reattached to the end of the handbrake end any help thanks mark p.s all new brake shoes fitted & adjusted till wheels turn freely when brake are adjusted
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Post by Phil Nottingham on Oct 8, 2007 18:56:42 GMT
USE SEARCH set to 999 days
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Post by dorsetflyer on Oct 20, 2007 16:31:48 GMT
Mark, your problem seems more like a problem with seized linkages somwhere. When you try and return your handbrake the cable will come off the pulleys and give the feeling that it's too long. Re-fit the inner cable on to the pulleys and then check all the linkages from the front to the rear to see if they are free. One thing I have found is that it only needs one slightly bent crossrod to stop the mech working on the rear wheel cylinder. These rods must be absolutely straight, otherwise you cannot get an even pull on the balance lever, and the drag link will only move slightly in the cylinder.
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Post by dorsetflyer on Oct 29, 2007 15:08:56 GMT
With the straight rods the car passed the MOT without anymore problems. If you get a seizure at the cylinder end, then operating the handbrake mech will cause the rod to bend. Something has to give in the end and it will be the weakest link.
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Post by mark21 on Nov 3, 2007 23:08:53 GMT
thank you for your advice cheers mark21
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Post by Phil Nottingham on Nov 3, 2007 23:47:41 GMT
Its important to realise that the Girling handbrake system was the final version of a 100% mechanical system from the 1930's that was considered far superior to the then common cable braked systems and even the new Lockheed hydaulics.
The first P4's retained 100% mechanical back brakes with just the fronts being hydraulic till the early 1950's as Rover along with most other responsible car makers then did not trust full hydraulics.
The P5 handbrake system is even a dash lever version of the P4 floor ones (itself from the P1-P3 era) and apart from the essential floating rear cylinders, the system depends on the rods being under very slight tension at all times (to stop rattles) If this is reversed so that they are under compression, even slightly, the rods are meant to bend but will remain so if parts are seized as DF warns.
Regular maintenance is essential and then the brakes will be more than adequate and give high readings for both hand and foot brake on the rolling road at MOT. Careless tyre fitters can easily put a kink in a rod jacking up the back axle.
Do not accept any less the perfect brakes, not just the low MOT standard as these are heavy cars to stop if the brakes fail and the autobox gives no engine braking most of the time, especialy the BW35 box.
The brakes should be highly efficient as designed. Remember half the dual circuit is the handbrake.
I dare you to test your handbrake with one hand, to see if it will pull up the car in a straightline quickly, safely and without locking a back wheel from 20mph, if it will not then sort it out fast. You may come to regret it if you you do not!
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Post by Warwick (Ozcoupe) on Nov 4, 2007 3:33:30 GMT
Thanks DF and Phil for taking the time to expand on your replies to this one. It hadn't occurred to me why the handbrake operates as it does. It just looked like a novel and rather unnecessarily complicated way of operating the rear shoes.
But now it all makes sense and I can cross one of my main concerns off the list. Back around 6 months ago when I was an extreme P5 novice, instead of just the significant one I am now, I asked the forum about possible dual-circuit conversions. As I indicated then, dual-circuit brakes are one of those advances that I believe to be almost essential and driving a car without that reserve of braking capacity is slightly worrying.
I presume that what I can draw from your comments Phil is that since the hand-brake design is a left-over from the mechanical braking system (and I can see this now that I look at the design again), it operates the rear brakes as effectively as the hydraulics do.
Therefore, unlike many cars (and probably no modern cars) the hand-brake IS the second circuit and should pull the car up just as well as the hydraulic system would if half of it had failed, albeit with perhaps a bit more effort.
Of course, this assumes that the entire braking system is in good condition and well-maintained; which is of course the only way it should be.
Warwick.
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Post by Phil Nottingham on Nov 4, 2007 10:12:07 GMT
Whilst the handbrake is very efficient a single leading/trailing shoe set up with relatively small narrow shoes cannot compensate for loss of the powerful front disks. Braking distances will still be much longer
The P4/P5 handbrake has long earned an unjustified view that it is poor - this is because its not maintained and is tampered with by both owners and mechanics who do not know what they are doing.
As such low efficiency is deemed quite "normal" and acceptable when it should be the opposite.
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Post by Deleted on Nov 4, 2007 11:40:48 GMT
For example, fully tightening the rear wheel cylinders when they are supposed to "float" on the backplate. Very clear in the workshop manual but not so obvious to a general mechanic as the special spring washers are small and sometimes have disintegrated due to age and rust. When I overhauled my rear brakes last year, the improvement in performance due to everything being free and properly set up was considerable. It is a good handbrake.
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Post by dorsetflyer on Nov 4, 2007 16:07:56 GMT
If my memory is correct the 'handbrake' readings are virtually the same as the hydraulic side of the rear shoes. So yes they should be, and are, if adjusted correctly very efficient even compared to modern day cars. The 'handbrake' efficiency figures for a single circuit braking system is far higher than the readings for the same in a dual braking circuit. Unfortunately most of us cannot equate what our handbrakes should be like when working on them under the car and its only when it goes on a rolling road that we know whether or not our labours have been worth it. At least I can relate to this now and unless the standard of my handbrake on my other cars is the same as that on my 3 litre then I won't be happy. One thing I have found out is that the self adjusting rear brakes on both my Sceptre and Vogue are still used today by Peugeot, some thirty to forty years later. The original designs were good enough to be copied and carried forward to this day. Again this uses the floating cylinder technique.
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Post by Phil Nottingham on Nov 4, 2007 16:43:02 GMT
And they always say to buy the new improved models with new features - this
As well as using old technology modern cars also take up far more roadspace than their 30s/40s/50s/60's equivalent as the Ford Mondeo is same size as the the P5 but it aims at was was the M1 Cortina market or even the Ford 10/Prefect of the 30s/40's but with far less interior space
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Post by dorsetflyer on Nov 4, 2007 17:52:57 GMT
Very true Phil about the size of cars increasing as each new mark of the same model is released. Then eventually an all new mini size car is announced which over the year grows and grows. Look at the old Mini against the new Mini. In comparison the new one is enormous, but is there much interior room for all that bulky outline. Sorry we are digressing from handbrakes.
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