Parking brake does not engage at all
#1
06-04-2018, 12:55 AM
Parking brake does not engage at all
I have never done this before. In fact, I am not sure how it works. But, I understand that there is a cable, a shoe, and magically the parking brake secures the car in place. Except no, at least one of the components of the parking brake system is not working. It has been this way since before I obtained the Jag.
When I pull on the lever, the brake light doesn’t come on, although I do feel resistance from the lever, there is no ratchetting going on. I confirm by putting the car in Neutral and giving it a push. Just as I suspect, it didn’t engage.
So, what are the steps to troubleshooting? Do I have to adjust the cable tension, the drum brake system itself, or are there other troubleshooting steps? What tools do I require to fix this? Is it an easy DIY or does it require a more experienced mechanic?
When I pull on the lever, the brake light doesn’t come on, although I do feel resistance from the lever, there is no ratchetting going on. I confirm by putting the car in Neutral and giving it a push. Just as I suspect, it didn’t engage.
So, what are the steps to troubleshooting? Do I have to adjust the cable tension, the drum brake system itself, or are there other troubleshooting steps? What tools do I require to fix this? Is it an easy DIY or does it require a more experienced mechanic?
#2
06-04-2018, 04:04 AM
Here's the relevant JTIS section describing the Parking Brake:
PARKING BRAKE.pdf
1. Cable Adjustment
PARKING BRAKE - Cable Adjustment.pdf
2. Shoe Adjustment
PARKING BRAKE - Shoe and Lining Adjustment.pdf
The warning light is triggered by a switch on the hand lever assembly.
Graham
PARKING BRAKE.pdf
1. Cable Adjustment
PARKING BRAKE - Cable Adjustment.pdf
2. Shoe Adjustment
PARKING BRAKE - Shoe and Lining Adjustment.pdf
The warning light is triggered by a switch on the hand lever assembly.
Graham
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giandanielxk8 (06-04-2018)
#3
06-04-2018, 04:32 AM
Veteran Member
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giandanielxk8 (06-04-2018)
#5
06-04-2018, 06:04 PM
Veteran Member
If I were trouble shooting this one, I'd raise the rear of the car and take a look at the brake adjustment connection. One wire comes back from the front actuator. Terminates in a connector that has a curled U shaped edge in the back. This curl accepts the center of the one cable that terminates in each of the rear wheels. Think of it this way, the one cable terminates one of its ends in each rear wheel braking assembly. Pull on this cable and parking brake shoes are actuated. As you can imagine this assembly that joins the rear cable to the motion of the actuator cable is pretty much centered between the 2 wheels. This way any motion moves the parking brake shoe in each wheel equally.
There is a nut to adjust the "pull" on that rear cable. I mention this because you'll find this nut needs to be turned a lot to properly adjust the tension on the parking brake shoes. At least that's how mine is set up. FWIW, the adjustment nut is almost all the way down on the threaded portion of this adjuster for me.
Glendanial, if you had a helper I'd ask them to pull on the actuator while I looked at the adjuster I just mentioned. Does it move forward? If so the actuator and cable to the adjuster is working OK. Next figure if it moves forward enough to lock the wheel (adjuster nut)
Next check the adjustment. I found I needed to use a air compressor ratchet for the adjustment - like I said it needs a lot of turns to get down to where it moves the brake shoe into position when "pulled". You'd be pretty frustrated doing this with an open end wrench.
If you need to pull the wheel to trouble shoot the parking brake at the wheel level, you'll see that the parking brake mechanism is a small version of the drum brakes on any car from the 1960's (pre disk brake world). Same springs, shoes, adjuster. Just a lot easier to manage because these springs are much smaller. I used to hate changing drum brakes this wasn't too bad at all in the end.
If you need photos of the parking brake shoes/springs/adjuster, refer to Chilly Philly's photos in his Rear Wheel bearing write up: https://www.jaguarforums.com/forum/x...+wheel+bearing.
Hope its not too wordy mate. Good luck fixing it.
John
There is a nut to adjust the "pull" on that rear cable. I mention this because you'll find this nut needs to be turned a lot to properly adjust the tension on the parking brake shoes. At least that's how mine is set up. FWIW, the adjustment nut is almost all the way down on the threaded portion of this adjuster for me.
Glendanial, if you had a helper I'd ask them to pull on the actuator while I looked at the adjuster I just mentioned. Does it move forward? If so the actuator and cable to the adjuster is working OK. Next figure if it moves forward enough to lock the wheel (adjuster nut)
Next check the adjustment. I found I needed to use a air compressor ratchet for the adjustment - like I said it needs a lot of turns to get down to where it moves the brake shoe into position when "pulled". You'd be pretty frustrated doing this with an open end wrench.
If you need to pull the wheel to trouble shoot the parking brake at the wheel level, you'll see that the parking brake mechanism is a small version of the drum brakes on any car from the 1960's (pre disk brake world). Same springs, shoes, adjuster. Just a lot easier to manage because these springs are much smaller. I used to hate changing drum brakes this wasn't too bad at all in the end.
If you need photos of the parking brake shoes/springs/adjuster, refer to Chilly Philly's photos in his Rear Wheel bearing write up: https://www.jaguarforums.com/forum/x...+wheel+bearing.
Hope its not too wordy mate. Good luck fixing it.
John
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dbtk44 (06-11-2018),
giandanielxk8 (06-13-2018)
#6
03-24-2020, 02:48 PM
Sorry for the necropost, but seeing that this is my thread and that I never got around to solving this due to other priorities, I feel it's ok to resurrect it.
I checked on the parking break lever. I do in fact have the microswitch still plugged in. However, actuating its plunger yields no Brake light on the dash. Before you go there, the Brake light on the dash does light up during the startup sequence.
I yanked the park brake all the way to the last click and put the car in neutral and attempted to give it a good push. It actually held the car. However, on the next to last click the car would roll. However, this is on flat ground. I'm pretty sure the car would roll even on the last click in even the most slight inclines. Johnken, if the weather allows it tomorrow, I'll check under the car to see if the cable needs adjusting.
I checked on the parking break lever. I do in fact have the microswitch still plugged in. However, actuating its plunger yields no Brake light on the dash. Before you go there, the Brake light on the dash does light up during the startup sequence.
I yanked the park brake all the way to the last click and put the car in neutral and attempted to give it a good push. It actually held the car. However, on the next to last click the car would roll. However, this is on flat ground. I'm pretty sure the car would roll even on the last click in even the most slight inclines. Johnken, if the weather allows it tomorrow, I'll check under the car to see if the cable needs adjusting.
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Johnken (03-24-2020)
#7
03-25-2020, 01:03 AM
Veteran Member
Easy to adjust but may need to be done in a few places
GD,
Your “necropost” makes me glad. So I’m not the only one who has a list of known jobs that I still haven’t got round to fixing... for years.
Jon89 has this issue recently and lots of good advice how to adjust it. Easy enough considering your current situation, but adjustments may be needed in 2 spots. See link to his thread below.
https://www.jaguarforums.com/forum/x...tments-229226/
Your “necropost” makes me glad. So I’m not the only one who has a list of known jobs that I still haven’t got round to fixing... for years.
Jon89 has this issue recently and lots of good advice how to adjust it. Easy enough considering your current situation, but adjustments may be needed in 2 spots. See link to his thread below.
https://www.jaguarforums.com/forum/x...tments-229226/
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giandanielxk8 (03-25-2020)
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#8
03-25-2020, 03:23 PM
Got around to it today. Adjusted the brake shoes and the cable. Now my park brake does work. It now holds the weight of the car in a 0° incline at the 4th click, and on a 30° incline at the 5 and 6th click.
However, the Brake indicator on the dashboard still does not light up when it is applied. I might need to replace the microswitch.
Does anyone know what spec microswitch I need to buy from Mouser?
However, the Brake indicator on the dashboard still does not light up when it is applied. I might need to replace the microswitch.
Does anyone know what spec microswitch I need to buy from Mouser?
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