Tech Tips: Summer 1999

On the subject of HIF4 carburetor conversions to late MGBs, if you cut the insulator blocks in half to clear the brake power booster, you will find that you also have to cut two notches in the heat shield to compensate for the movement of the throttle shaft.

The insulator blocks have a thickness of 1 1/8″, but rather than cutting them in half (at 9/16″) cut them at a thickness of’ 3/4″. By doing so, you will not have to notch the heat shield, and you’ll find there’s still plenty of room for low-profile air cleaners.

—Neil J. Brennan, Crofton, Maryland.

Many MGA owners experience problems with the brakes binding, especially after a brake system rebuild. The common complaint is that the brakes begin to drag as the car is driven, which in turn creates tremendous heat, and eventually stops the car, possibly damaging your new linings, pads, and discs.

The factory workshop manual (Moss #210-410) gives explicit instructions for setting the master cylinder pushrod, which sometimes cures the problem. However, even with proper free play in the pedal, the brakes can still bind up. The problem is that the master cylinder piston is not coming far enough forward to uncover the bleeder orifice that allows the expanded fluid to bleed into the reservoir.

The solution is simple: Add a shim between the master cylinder block and the cover plate. This shim allows the piston to come a little further forward, thus uncovering the bleeder orifice.

I cut my own shim from .020″ brass shim stock using the gasket (Moss #180-020) as a template, but allowing a 1″ diameter clearance hole for the brake piston. I actually used two #180-020 gaskets, modifying one to include the 1″ diameter hole, but leaving the other as standard.

—Mark Palmer, Lansdale, Pennsylvania.

After removing the seats and tracks from my MGB in order to thoroughly clean and re-carpet the floor, I found to my surprise that reinstalling the seats was a real hassle! But I came up with a solution: After unbolting and removing the seats, tracks, and shims, take the two rear track bolts and reinstall them back in place in the two rear holes—but from underneath the vehicle.

The bolts will protrude up through the soundproofing pad, the carpet, shims, and track, making it much easier to properly replace the seat tracks.

Unfortunately, you cannot do this with the bolts from underneath due to the cross member. However, purchase two 4-5″ bolts from the hardware store, cut the heads off, and hand holt them into place from inside the car. Once the tracks and seats are in place, remove one bolt at a time, reinstall the proper bolts, and fasten them down.

—Lou Radcliffe, Long Beach, California.

Can I offer a tip which might be useful to your readers, relating to the task of removing and replacing the starter motor on a ’67 MGB?

After removing the oil filter, distributor, and loosening the engine mount on the right hand side, I was confronted with the task of taking off the starter. The bottom securing bolt was OK, but the top bolt was a real problem.

It is located so close to the starter body that the use of a socket or ring spanner is impossible, leaving the use of an open-ended spanner as the only alternative. Unfortunately, I discovered the previous owner of the car had had a similar problem, and had burred over the holt head with (apparently) the use of a sloppy-sized open-ended spanner. This made removal of the bolt a lengthy and frustrating job, to say the least!

When I replaced the starter, I managed to obtain a replacement bolt which had a round head, but which had an Allen key recess in its head. Make sure you select a bolt that takes a robust key and future problems in this area will be avoided.

—Barry Eisenhauer, Mermaid Beach, Australia.

A fairly recent technical tip published in Moss Motoring outlined a procedure for the spring replacement on an MG. This was a good idea, but it doesn’t work for a Triumph because of the differences in parts. I’d like to suggest a modified version that works well for a Triumph, specifically for a TR4A, but I’m sure it applies to other Triumphs as well.

1. Lift front end of car and place on jackstands.

2. Remove both road wheels. (Springs should always be replaced in pairs.)

3. Loosen the two inner spring pan nuts on their studs until the bottom of the nuts are even with the bottom of their respective studs.

4. Place jack under spring pan so as to barely support the load, paying attention to its positioning, so that the other spring pan bolts can be removed.

5. Remove the bolt from the bottom trunnion assembly and swing vertical link out of the way.

6. Remove the four remaining outside nuts and bolts from the spring pan.

7. Lower jack.

8. Pry out spring and remove rubber washers.

9. Replace with new spring, and new rubber spring washers, top and bottom.

10. For reassembly, reverse procedure 1 through 6.

11. Repeat on opposite side.

I have found this method safe and requiring no special tools. I have recently replaced springs and shocks, front and rear, and can’t believe the difference. It feels like a new car!

—J. Clark Jones, M.D., Everett, Washington.