August 2018, FHC jobs start, Front Brakes

New Front Brakes

One of the first jobs I wanted to do on the new car when it came back from the bodyshop was to overhaul and upgrade the brakes.  Standard TR7 brakes are not as good as modern cars and as it had been parked up for some time they needed work anyway.

Princess 4 pot pad top, Standard TR7 pad below

 I decided that the Princess 4 pots like I already had on the DHC were the best cost effective option and would also provide some interchangeability between the cars.  I had also previously found a pair of calipers that needed a rebuild on Ebay and bought new stainless steel pistons with a seal kit to do the job.  The rebuild is not a difficult job and I also took the opportunity to drill them internally at the same time.

The Austin Princess had brakes with an unusual dual circuit system where two separate pipes fed each caliper. Some folks just link these circuits by an external pipe on the caliper but by drilling to link the two circuits inside the caliper is a much neater job in my opinion.

I pop the pistons out with an air line. This can be a bit dodgy so I use a piece of wood to catch them as you see here.  This allows them to come out enough to grip and remove easily.

Pistons are out and caliper halves are split. The bores look good after a quick cleanup so a coat of paint and ready to drill the internal link hole.  

I use a 1/8" bit (3.2mm) and drill carefully making sure the bit is straight until it breaks through into the gallery. This will be indicated by hitting the welding rod!  Your two separate fluid galleries are now linked inside the caliper. 

The new stainless pistons and seals can now be fitted using plenty of red brake grease, and the two halves of the caliper bolted together, not forgetting to include the spacers so they will fit over the vented discs.

Next job was the fit the new vented discs for the calipers to work on.  Looking around I found out that Toyota Supra 2.8 1982-86 looked ideal. They are 258mm diameter and 20mm thick and luckily pretty cheap as well.  My local machine shop turned me up a couple of adapters to mount them on the TR7 hubs and it all bolted together nicely.

Toyota Supra 2.8 Vented Disc

Hub Adapter

Complete Brake Kit Ready to Fit

Disc and Caliper Fitted Showing Alignment

Pads Fitted Showing Correct Positioning

Final Result. Excellent.

I also used a set of Goodridge stainless hoses to complete the front brake setup.

2011, Brakes and Wheels

So its 2011.  There is the new project parked in the garage and my original "everyday" TR7 is parked outside under a nice cover. Not ideal but its only a temporary arrangement isn't it ?
I wasn't quite ready to really start work on the project but had started to strip stuff off and get rid of some of the scrap items like the ruined carpets etc.

In the meantime I regarded the "everyday" car as a kind of test bed for stuff I planned to use on the new one and one of the first things that came along was a set of 4 pot brakes.  They were advertised on Ebay starting at £50 but with no pictures and a vague description..  When I contacted the bloke I found he was not very helpful but said he had taken them off a TR7 rally car and they were complete and ready to bolt straight on.  What to do?
I thought £50 was worth a gamble,  so I placed a bid and was amazed to find out a couple of days later they were mine!
Turns out it was the small Rimmers upgrade kit using Princess 4 pot callipers and vented discs of 244mm diameter and 20mm thick. It would have cost at least £250 to buy so that was a good deal and they went onto the car.

Princess 4-pots fitted

 

The handbrake on my everyday TR7 had always been poor so I decided it was worth having it apart to sort out.   The rear brakes have a self-adjuster mechanism but it hardly ever works properly and that was also going to mess up the handbrake operation.  I had a new kit to replace all the adjuster mechanism in stock (another Ebay purchase) so this was the time to use it.

Standard wheels on a TR7 are 13" diameter and many TR7 brake upgrades need bigger wheels to fit them inside, so when a new set of 14" x 6" Minilite style turned up at a very good price they went into stock as well.  The wheels needed taper fitting nuts so I had to get some of those to match.

New "Minilite" style wheels fitted

 Replacement wheels are a bit of a concern on TR7's.  The standard wheels are hub-centric meaning that they are a close fit on the boss in the centre of the hub to give them their accurate location.  The wheelnuts do not locate the wheels they just hold them on the hub.
Most replacement wheels are located by the studs and can sometimes cause vibration problems if the wheels are not centred accurately.  Time would tell if mine were OK..