1982 xj6 series 3




























The brake pedal doesn't feel as stiff as it should. Braking time is slower as well(have to hit the brakes a good distance away from a stop sign to fully stop in time). Rotors and pads are good, is there a way to test the master cylinder in place? Also, what are the two connection on top of the cap of the master cylinder?

 

If you add your model and year to your signature it will be on every post you make.
No need then to add it .

 

Ahunt,

Have you picked up the factory service manual for your car yet? Starting there, or in the parts catalog that goes with it, will help with answers to many of the questions you've had over the past few weeks. (And I really enjoy just flipping through both, plus the Haynes, for fun and to get to know my car better, but that's me.)

Really, there's very little that hasn't been covered in some form by the ten years or so of posts at our disposal in this forum. Aside from basic facts and information, there are also a wealth of troubleshooting guides in this and the other forum (Jag Lovers) that you should become familiar with. I always start digging first and recommend you try the same.

After that, the kind, patient and experienced folks who inhabit this forum are always happy to help if possible!

Kind regards,

Andrew.

 

The first thing you want to do is remove the wheels and bleed your brakes. If you observe a few considerations you'll have more success.


Remove all the old fluid from the master first using a turkey baster type device. Then refill it with fresh fluid. Then remove the wheels and bleed the brakes using the stomp and hold method. When bleeding the brakes you will have an opportunity to inspect the calipers and rotors.


Typically the rear brake system fails for a variety of reasons related to their location on the car. This causes a spongy pedal. Typically one side of the caliper freezes, then the rotor warps, then the warped disk pushes one pad and piston far off the surface of the caliper. That requires great pedal travel to take up the space between the pad and the warped disk. As the pad wears on the frozen side, the disk then has to flex under pressure to make contact causing a spongy feeling. Keep in mind that the master cylinder is designed so that the rear brakes either have to get to a certain pressure or have excessive travel before the front fluid circuit is applied. All this adds up to terrible braking feel and performance if the rears are not in ideal condition.


One way you can test this is to use put a flex line clamp on the flex line for the rear brakes which is located on the USA passenger side just in front of the rear IRS cage. Bleed system and clamp the line, that simulates working rear brakes. If you get your pedal back then your rear circuit needs a total service. If you don't then the master cylinder may be leaking internally. Many big box auto parts stores sell line clamps.


After accessing the results of the test you may find that you need to completely rebuild the rears system, new pads, rotors, calipers then install a new master cylinder because yours is probably torn up from the excessive travel. None of this is terribly expensive, however dropping the IRS to re-do the rear brakes is a considerable job and looks nightmarish for the DIY'er who may be used to servicing conventional outboard brakes.

 

A very exhausting and thorough discussion.


Indeed, your car may be a two wheel brake car. Most likely the fronts only!!


The cap has two wires, a slick little system to denote brake fluid level. If the float drops too far, for lack of fluid, it closes a warning circuit nd a warning lamp goes on in the dash cluster.


Mine worked at one time. But, a spade busted. I've a spare or two, but, in poor shape.


So, I just do it the old way. Motor stables most Saturday AM. Bonnets up. Liquids checked. Oil, coolant, trans mission, washer, power steering and brake reservoir.


Fixing fronts is not all that bad.


fixing rears is much more complex. Three ways to do it.
A. Drop the cage and do it in the open or even on a bench.
B. In situ, on your back, through the cage.
C. In situ, off each side , by removing the coil overs and opening the U Joint.


A lift helps hugely. but, few of us are so fortunate.


I shoped ut my rears after shopping for losded calipers via Rockauto. good price, no core charge.


Carl
Car