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MG TD TF 1500 - Brakes ???

Recently topped off brake fluid, after which unusually hard pedal (< 3/4") travel but poor brake performance. Any thoughts, where should I start/focus other than pulling all four wheels and doing brakes from scratch
JON LEVINE

Sure sounds like blocked/collapsed brake flex hose(s) or some other blockage somewhere in the system. I had ancient blocked hoses and was getting hard peddle but almost no braking on the right front. Once the right front brake engaged it did not want to let go.

Jud
J K Chapin

While Jud's post is certainly a possibility I see no connection other than coincidence, to topping off the fluid and the symptoms you are experiencing.
John Quilter (TD8986)

Probably frozen pistons in slave cyls.Slack off the adjusters in turn and try the pedal each time, any difference between them will indicate the faulty cyl. If a cyl makes no difference then that is the one at fault.
Ray TF 2884
Ray Lee

Were the brakes working prior to the top off? Has the car been sitting?


Bruce Cunha

Car was sitting and on a couple of runs poor braking( pedal soft) , on inspection master low so refilled and now high hard pedal and worst braking
JON LEVINE

Bleed em?
efh Haskell

I wonder if the cap is plugged and the reservoir is overfilled, lacks air space.
JIM N

Before I screw something up, should the indentation on the top of the reservoir be "open", so if it's plugged I should ream it open
???
JON LEVINE

Jon, Pictures of what you are speaking of would be helpful
W A Chasser

I installed a remote reservoir years ago so I'm not sure this is or isn't for our T cars, but I'd run a needle or wire into the hole on the side of the hex to make sure it isn't plugged and blow compressed air through all holes to verify it is clear.

Note instructions for filling.

JIM N

Good article on our brakes. It doesn't make any mention on the consequences of overfilling.

https://www.bobmccluskey.com/brakes.shtml

Interesting image in it.
Source: MG Midget Workshop Manual Iss 3 1/54

By its construction, it is supposed to have a small air reserve at the top, but it still could use venting as the level drops and rises each time the pedal is depressed. If the cap is plugged or flooded, it may not vent and operate right.

JIM N

I can confirm from personal experience (with a 1973 Midget) that if the vent hole is blocked it will give an unusually hard pedal.

But after parking up on a run out on return to the car the pedal went to the floor and needed pumping up.

This was just after I'd fitted new parts and bleed the brakes and unusually had a mate help me and I commented that I'd never managed to get the pedal that firm by myself.

Mine was because the plastic cap did not hole in it from manufacture but I'd not noticed before because the cap was previously on the clutch and I must have swapped over caps when toping up fluid to both reservoirs.
Nigel Atkins

This thread was discussed between 24/06/2021 and 28/06/2021

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