Series 1 E type braking

[kirk]

Hi guys, thank you for accepting my request. 

I have recently restored my late dad’s series 1 E type 3.8 with the Kelsey Hayes servo. 

After about 4 miles, the rear brakes lock up gradually and there’s no going anywhere for about 20 minutes. Once the brakes free up she is fine for the rest of the journey... 

Any ideas? 

 

Best, Kirk 

[Jaguar Owners Club]

Hi Kirk....welcome to the Forum

It sounds like the master cylinder is applying the pressure to the rear brakes (unless there is a compensator valve on the rear suspension).

It would be quite easy to diagnose by releasing the pressure on the rear brake lines attached to the Master Cylinder by cracking off the unions and if the brakes release then the problem is with the Master Cylinder.
Be careful to carefully crack the unions loose as brake fluid will be expelled. Also best to cover any paintwork and have a watering can handy to pour over any fluid to neutralise it.

If this does not produce any results then I would look at the servo being instrumental in applying pressure to the brake pedal....but if this were the case then you would imagine the front brakes to be applied and not the rears.

Let us know how you get on with it.

[NWG]

Kirk

You need to be systematic with your checks and a good starting point is to suspect that the interior of the rear brake hose is collapsing. This occurs on many cars when the hose interior collapses and starts to act like a one way valve , eventually locking up the brakes.

If you find that is the issue, then change the front hoses also AND ENSURE you flush the system, otherwise all the sediment from the hose interior is going to cause further problems.