| Author | Message | ||
     Kay C. Wiese New User Username: wiese Post Number: 7 Registered: 9-2015 |
Hi: I have a problem that is baffling me: On my new to me 1979 Silver Shadow II (LHD) the parking brake is not holding. It is the foot operated kind. It can be pressed down and the parking brake will work on the rear calibers, but it is not holding/locking with the release mechanism under the dash. It appears that all the springs are there and the shaft goes through the opening of the catch that is connected to the release lever, but it's not "catching". Can anybody share their ideas or has anybody had a similar problem? Thanks, Kay | ||
| Robert Noel Reddington Grand Master Username: bob_uk Post Number: 551 Registered: 5-2015 |
I have never seen a foot operated parking brake on a Shadow. Drop the trim from around the mechanism. Then using a bright light observe how the release lever works.Does it click and move around as the pedal is pushed down. Can you feel the ratchet when the release lever is touched. Once you done those tests remove the mechanism. Follow your nose and take photos as you go. Once on the bench the fault will be obvious. Check the rachet pawl( the little steel thingy that engages with the ratchet teeth). Somethings a bit filing to give better definition to the teeth and pawl fixes the problem. Also building a worn pawl with weld and reshaping works. Disconnect handbrake switch wires. Note the hand brake cable is earthed should it touch something live whilst being pulled around, a dead short will result and possible fire. So disconnect battery. Mine is the pull and twist to release type. The cable disconnects from the bottom and the whole assembly unbolts for service/repair. Yours will come apart about the same. Grease pivots and things. Once fixed its worth referring to chapter G for setting up of the relay lever compensator under the car. There's a diagram and measurements. These settings are set in the factory I should never need adjusting unless a cable is replaced. But it attracts tinkerers who are clueless. Also the relay lever pivots like greasing. Once done forget for 10 years. Also undo the long nut at the caliper. Swing the 2 arms of the caliper out apply oil to pivots and swing to and throw. Reassemble adjust till rotor locks back off till just free then 1/2 turn out for luck. Because your one is different. Another method is check reserve travel. By rule of thumb a fully applied handbrake should be a 3rd to 1/2 way of it available travel. So if the system will take it the long nuts at the caliper can be even further backed off thus ensuring long pad life.If too loose the efficiency of the angles will be lost. 1 extra whole turn is ok though. I can easily turn the rear hubs on my car without the wheel or levers. If you find your caliper arms are stiff. Depressurize system. Remove hand brake and main big pads. Place bowl under caliper. Clean the handbrake levers with wire brush and brake cleaner. Then keep oiling and swinging the arms until they are free. Acetone and transmission fluid works well. After clean rotor with brake cleaner refit pads. The outer pad retaining spring rusts and breaks. But the springs are nothing special. Buy one long spring and cut it up and then bend a coil out to fit. 2 per car. The inner pad retaining springs are much stronger. So stronger outer springs will be fine. This type of handbrake caliper was designed by Dunlop for the E type Jag. About 1960. | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 1689 Registered: 6-2009 |
Kay, I have not had a similar problem but will be happy to take photos on LRK37110 if those could be of any help. Based upon what I recall of how these work it might be a broken spring on the catch mechanism. SRH33576 has the hand pull parking break mechanism, not the foot mechanism. It probably had something to do with what was customary in a given delivery market, and foot operation is far more common in North America than the kind of hand mechanism in the Shadow is (at least by the era when they were produced - I recall a number of much older cars the employed these). Brian | ||
| Kay C. Wiese New User Username: wiese Post Number: 8 Registered: 9-2015 |
Thank you Robert and Brian for your suggestions and comments. Apparently, according to the Workshop Service Manual, all LHD cars have this foot operated parking brake. I looked up the mechanism and there is an actuator that locks the sprag shaft. In my case it is not holding it. There is a procedure in the workshop manual to adjust the actuator plate and I will follow it and hopefully this will make the problem go away. Otherwise, it may be that the shaft and plate is worn too much. | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 1690 Registered: 6-2009 |
Kay, Unless something is really, really weird the likelihood that the shaft or plate is "worn too much" is incredibly remote. My guess is that whatever is supposed to keep the actuator plate cocked such that it grabs the shaft (I haven't looked at mine, but the hand version has grooves cut into it) has gone wonky. It's been so long since I set the parking brake that I can't remember whether this is a "foot push lock/foot push unlock" toggle type action or a "foot push lock/release pull unlock" type. Brian | ||
| Kay C. Wiese New User Username: wiese Post Number: 9 Registered: 9-2015 |
By following the instructions for adjusting the mechanism given in the workshop manual this issue is now resolved. |
