Brake Upgrade

One of the hardest parts of writing articles is writing about stuff that has been written about hundreds of times, so here is my attempt to keep it interesting. One of the most common questions over the years is about braking. With bigger tires and wheels sometimes this becomes an issue so here is my low cost solution that seems to satisfy most drivers. Not everyone has to spend hundreds of dollars to get their car to stop. My first suggestion is to do a booster upgrade, I will talk about up grading a TR6 booster to an 8" universal, single or dual is the same work. You can purchase a universal 8" booster for about $100.00 average cost. If your brake master is old now is the time to replace it, if yours is worn it will fail, don’t buy an economy one, OEM quality , Britishparts northwest has a decent priced one . Installing the booster is not a direct fit, nor is the master to it. You will have to oblong the firewall holes a little and rework a clevis to fit , on a TR6 a spacer is used between the booster and fire wall , you will have to make a thinner one , this can be made out of any ½" material ( I do have aluminum ones ) wood , Lexan , metal and fiberglass can be used. The push rod depth will have to be set, also this measurement is taken from the old booster as is the clevis length. Once these modifications have been made the booster is ready to bolt up. Now for the brake master, you have to oblong the master cylinder mounting flange holes, a file will do this, measure and fit, make sure you pre fit the master to booster to make sure you have push rod clearance, a new longer adjusting bolt might be needed to get the right distance ( a button Allen head bolt works well if a longer one is needed). Before you re assemble check the PDW valve for leakage, I do have a fix for that if needed, the UK cars did not use a PDW valve, so the fix I do is not dangerous. It is always better to bench bleed the master before you install to get all the air out of it , then install the brake lines and do a power bleed on all the wheels , once the car is ready for the road, test it in your driveway first. The next step if needed is caliper and rear cylinder upgrades, but try this first. MGB’s can be fitted the same way but use a 7" booster I upgrade the master at the same time on a MGB. On a TR6 with the bigger booster you can use Morgan rear cylinders and get a good rear brake feel. One of your questions might be WHY? The bigger the booster the more pressure you get at the wheels with the same foot pressure. On the average this is more than adequate to get better stopping power. I have a full set of pictures of the install if needed, email me at and I will send them to you and answer any questions.


I am, after 7 years going to finish my wife’s TR6 , it will be the last personal car I do so no budget on this one , A/C ,electric P/S from EZ steer out of Holland, P/W , cruise , automatic , V6 CHEVY , plus a full suspension make over, just to mention a few things , I will go into the upgrades as they are installed, I hope to take the finished car to San Diego next Oct. .

Bill Sinclair