Brakes are naturally a very important part of a vehicles operating system. What good is going fast if you can’t stop the vehicle? We decided to change out the brake system on my 1985 Jaguar XJ6 because the car sat for such a long time (Over ten years). I wanted to replace the power brake booster and the master cylinder with reservoir.

Researching online parts dealers, we found several that sold what we needed. Some showed what we needed as “out of stock”. Of what I could find available was of course very expensive. A new brake servo assembly vacuum booster could cost upwards of $400, including a $150 core charge. Add to that the master cylinder at $180, a reservoir for $100 (used) and a new red plastic vacuum valve for the brake booster to engine manifold hose at another $20.

Just these parts alone can cost you up to $550. This does not include any brake fluid, wheel calipers, brake lines, pads or labor. Yes, it could be pretty expensive but it depends on how you look at it. Do you want to stop the car? Isn’t your vehicle worth every penny you put into it? Dent just one fender and see how much you’ll spend to repair it.

Don’t worry, we were actually able to come up with something that was a little easier on the budget. We went to our local boneyard (a U-Pull it auto salvage yard), found a 1994 Dodge Caravan and removed the master cylinder from it. The cost? $10.60. Don’t forget to bench bleed the master cylinder before you install it on the Jaguar. You won’t have any pressure in the brakes for stopping, unless you get all the air out. Go here to see how.

The vacuum booster was found online, new at Auto Parts Warehouse. Manufactured by A-1 Cardone, part #A1535950 (APW part number). It cost me $149.67, plus a $54.90 core charge. As of this writing, I am still trying to get my core money returned. They never sent me an RMA. That’s a “Return Merchandise Authorization” number. I’m still waiting to hear back from an email I sent them about it. Otherwise, it was a perfect fit. I found out afterwards that you can get one from Rock Auto. Also manufactured by A-1 Cardone, part #535950 (Rock Auto part number). It sells for $132.89, plus a core charge of $45.

Install the new vacuum booster to the mounting block on the firewall of the Jaguar the same way you took the old one off. The pushrod in the vacuum booster will have to be adjusted to just touch the inside of the master cylinders diaphragm when installed. Unscrew the bolt at the end of the pushrod several turns. Replace the master cylinder, feeling for the end of the rod to bottom out just as the master cylinder is completely snugged down.

As you know, the Jaguars’ brake line fittings are metric and the Caravans’ brake lines are standard SAE. The original setup on the Jaguar won’t work with the new master cylinder from the Dodge unless we do a little customizing. At Advance Auto, I purchased two 3/16” by 20” brake lines. Be sure to get the one with the ball fitting ends, not the standard flare ends. They were $4.99 each plus tax. After the fact, we realized we could have purchased just one line at about 40” for less money. You’ll see why one line will do in a moment.

Back at Hippie’s Hot Rods, we removed the original brake lines from where they are mounted to the fender. From the original brake lines we cut the tubing to remove the original fittings, discarding the original brake lines. Assuming you did purchase new 40” brake line, use a tube cutter and cut the new line in two equal halves. Remove the new fittings and replace with the original fittings resting towards the ends that still have the flare on each of the new tubing. Snug down each new brake line into place on the fender.

Next, carefully bend the tubing along the fender well so they come up from under the master cylinder on the fender side. Mark the tubing with enough length so you can curve the tubing around to point straight into each of the master cylinders’ housings.  Don’t forget to cross the brake lines sending the rear line to the front of the master cylinder and the front line to the rear of the master cylinder. It sounds goofy but this is the way it has to be for it to work properly on the car.

Now remove the brake lines and cut to length. Replace a new line fitting and with a flaring tool, flare the ends of each brake line. Now you have a metric fitting at one end and a standard SAE fitting at the other end. You can now install both brake lines. Please don’t forget to bleed all the wheel cylinders after completing this procedure. There is no other way to remove the air in the new lines other than bleeding each of the four wheel calipers.

Using this setup, there will be just enough room to replace the flasher relay back to its original location.