• Hey Guest!
    British Car Forum has been supporting enthusiasts for over 25 years by providing a great place to share our love for British cars. You can support our efforts by upgrading your membership for less than the dues of most car clubs. There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Upgraded members don't see this banner, nor will you see the Google ads that appear on the site.)
Tips
Tips

Wedge 1980 TR7 Brake master Question

Share this page

A

Aeroweld3033

Member
Offline
hey folks does anyone know the bore size of the stock master cylinder on yee ole wedges? or to make my life even easier, does anyone know of any other masters that bolt right onto that booster, theres got to be something! cant find a new Tr7 master for under $200 but im seeing plenty of general spec built ones for around 50 to 80 which even seem better ( bigger bore sizes and casted of aluminum ) but i cant get companies to email me back with mounting dimensions . . . so any help will be appreciated. . not naerly as concerned with originality as i am with getting her on the road
 
TR8Todd has a few options I am sure he would pass on to you. I know of a few bolt on master but have no clue what they are from.
 
Unless you are changing brake calipers, your best bet is to keep the stock bore size. Bigger is not better. Brake masters are sized according to the cross sectional area of the pistons in the brake calipers and the rear wheel cylinders. Other things come into play such as pedal ratio and brake booster area. $200 is a very fair price for a brake master that you know will work properly and won't require all kinds of other potentially costly mods to make fit. If you are determined to try and use a $50 Chinese master, then take careful measurements of the stock TR7 master and use that as a guide to pick out the new one. Sites like Summit will provide measured drawings of the parts they sell and in some cases application. The biggest issue you will have to overcome is the small size of the opening in the booster that the master inserts into. Most aftermarket MC bores are between 7/8" and 1 1/8'. The castings are too large to fit into the TR7 booster. Bigger MCs are great if you go to larger caliper bores or add rear disc brakes. In those cases, you will want to push more fluid with a given stroke of the brake pedal. You will also need to buy a handful of brake line adapter fittings, and plan on modifying the brake pedal and the push rod. Buy the new one, a good used one, or rebuild the one you have.
 
i understand bigger isnt always better which why im still trying to find out what the stock bore size is for the 7.. . and thanks for the info
 
Bore size 7/8". Mounting hole spread center to center is 2.25 ". Machined end that fits into booster is slightly less than 1.2".
 
Back
Top