Kit Car Brake Identification / Problems?

[Mitchy88]

The brakes on my JZR three wheeled trike have become stuck, can anybody offer advice?

The kit has been in storage for the last year and i recently discovered that a younger cousin decided to play ‘racer’ whilst it was up on the stands, pumping all the pedals and being a silly bugger.

The breaks are now firmly locked and I have no idea how to release them. Also, can anybody identify the make and model? Id like to buy some now disks as these are looking a little tired!

Many thanks, Mitch

[Sam_68]

The JZR front uprights, brakes and calipers are Ford Cortina.

In terms of releasing them, it sounds as though they may be locked on due to fluid pressure, so try unscrewing the bleed nipples to relieve the pressure (holding a cloth over them, as they may squirt fluid out)...but you then need to investigate why they had locked on in this way. It tends to suggest that the master cylinder piston or pedal is partly seized (and/or the pushrod length/pedal adjustment is incorrect), so that the reservoir port is not being uncovered desipite the fact that the brake pedal is not being pressed, though I have experienced similar symptoms with internally collapsed brake hoses.

That's assuming it's not just that the pads have welded themselves to the discs during storage, in which case brute force usually works a treat.

[Mitchy88]

Thanks for the advice, funds permitting a fancy changing the disks as they are letting the front end down a little at the moment. Rest of the car has had a spruce up and they look tired.

The brakes were working perfectly before storage so im hoping there isn’t a major issue to be resolved.

I know little about the way brake systems work but had assumed that they were locked due to them being pumped without the ignition being on. The brake pedal on my scenic stiffens up immediately if its pumped without the engine running. (Could be way off the mark? Is that due to the servo assistance?)

If they have just stiffened up, which method of brute force should be used? Should I drop it down and roll it back and forth or do the pads need to be pulled away from the disks?

Sorry if any of the above seems daft, im a bit of a novice!

P.S Love the Sylva, I wish I was the same position as I was when you mentioned you may let it go. (Some time ago!) Unfortunately a roof now seems necessary!

[Sam_68]

Mitchy88 said:

If they have just stiffened up, which method of brute force should be used? Should I drop it down and roll it back and forth or do the pads need to be pulled away from the disks?

Sorry, that was a slightly tongue-in-cheek comment on my part.

If you're fairly confident that it's not hydraulic pressure holding the brakes on, try tapping the edge of the disc with a hammer (not really belting it, which could potentially damage the disc); the shock will usually be enough to break the 'bond' between pad and disc. If that fails try dropping it back on its wheels and trying to drive it forward with the engine (ie. engage 1st and slip the clutch), but be careful 'cos if it is just stuck pads, they will free off with a jolt and the car could suddenly lurch forward.

If you can roll it (or drive it) back and forth even slightly, then it isn't the pads stuck to the discs, it's the calipers binding (locked on due to hydraulic pressure as suggested above, or - remote possibility - caliper pistons seized).

eta:

Mitchy88 said:

The brake pedal on my scenic stiffens up immediately if its pumped without the engine running. (Could be way off the mark? Is that due to the servo assistance?)

Yes, that's the servo assistance. Doesn't apply to your JZR's unservo'd brakes.

Edited by Sam_68 on Friday 16th July 17:54

[Mitchy88]

Thankyou for the advice, seems I may have it cracked!

After giving the carbs a thorough clean I sat her down and slowly eased forwards, there was a slight crack as the bond broke and I was away!

Only managed to drive up and down the street a few times but all seems well. The brakes are binding slightly, could this be due to the surface rust which appears to have formed a slight crust on the disks? If so im hoping to ‘burn’ it off on the way to the mot center next week….

Thanks, Mitch

[Sam_68]

Mitchy88 said:

The brakes are binding slightly, could this be due to the surface rust which appears to have formed a slight crust on the disks?

Yes, that's entirely likely.... just in need of a bit of a workout.

[Mitchy88]

Thank you for the advice, after some sustained braking the problem seems to be getting better. I shall be heading out Sunday morning for a proper 'shake down' hopefully all is well!