Brakes

olonas · Post by **olonas** » Wed Oct 02, 2002 2:05 pm

When I aquired my Traveller, I was advised that all the braking system had been renewed. They do work to at least MOT pass standard but nowhere near as well as my saloon, or other Minors I 've driven. Both have 7" rear and 8" front all standard systems.
My problem is, in addition to the reduced efficiency, the pedal travel is also excessive on the Traveller, compared to the saloon. There is definitely no air present. The pedal is a bit "springy" rather than spongy and doesn't "pump up."
I've examined the system, it does have new shoes, drums, wheel cylinders and pipes throughout. Adjustment is correct. The only remaining prime suspect must be the master cylinder. I don't suspect the pushrod adjustment has been fiddled with. The master cylinder body doesn't look new but could have been fitted with new seals etc.
Does anyone agree with my diagnosis. I don't really want to renew the master cylinder and still have the same problem. Any other suggestions would also be appreciated.

Post by **Cam** » Wed Oct 02, 2002 3:08 pm

The pedal should not be springy or spongy but quite firm when pressed.

Have you checked that all the wheels are braking as they should? (jacking up & testing etc.)

the only reason that the feel of the pedal should change like that is if a slave cylinder has seized or the pipe is blocked/crushed.

The feel also changes if you fit cylinders with larger bores. but if your system is standard and if all the wheels are operational there is only the master cylinder left.

Not nice, I replaced one before I realised that you can bend the torsion bar out of the way to remove the mounting pins.....D'OH!!!!

Make absolutely sure that there are no air locks anywhere, the master cylinder is full and also that the small hole in the cap on the top of the master cylinder is not blocked before you buy a master cylinder.

Hope this helps.

Cam.

Post by **Willie** » Wed Oct 02, 2002 6:35 pm

Lo, by any chance are the brakes noticeably better in reverse
than when going forward? What year is your traveller (have the
8" front brakes been retro-fitted)?
Willie

olonas · Post by **olonas** » Wed Oct 02, 2002 7:16 pm

Cam, thanks, yes i know about the torsion bar bending trick! It works well.
Yes, the vent is clear. Plus the other possibles are all ok. New flexi hoses fitted as well so I doubt they are "ballooning."
Willie, thanks, 1957 Traveller with larger front drums fitted. The brakes are not as efficient in reverse.
I have leaned towards the master cylinder being at fault for some time but was hoping that someone had maybe come across a similar problem to which the solution was glaringly simple. It may not do any harm to change the master cylinder I know then that the whole sysem IS new. I have two good master cylinders a 7/8" and a 13/16", the latter new and unused.
Out with the torsion bar bending kit, no doubt.

Post by **Willie** » Wed Oct 02, 2002 8:26 pm

I hope you are aware that the later(8"front brakes) system used
the SMALLER (13/16") bore master cylinder. this give more
pressure than the 7/8" bore. I must say that I noticed no
difference when I uprated my '57 car.
Willie

Post by **Willie** » Wed Oct 02, 2002 8:32 pm

Lo again, when you remove the Master Cylinder using the
'bend the torsion bar' method fit the cylinder fixing bolts
back in the opposite direction so that the nuts are now
next to the torsion bar. This obviously removes the need
to bend the bar in future BUT do check that when the nuts
are done up the ends of the bolts are not rubbing on the
Torsion Bar......I had to grind metal from the end of the
bolts..If you leave them rubbing the bar will not last long
Willie

olonas · Post by **olonas** » Thu Oct 03, 2002 8:15 am

Thanks for that, Willie. When I upgraded my 1962 saloon's front brakes to 8" I fitted a 13/16" master cylinder. No I didn't notice any difference either. I did refit the securing bolts with the nuts towards the torsion bar. there was clearance but I took a bit off (the bolt & nut) just to be sure.
I just wonder if there has been a cock a doodle diddley up if the Traveller master cylinder has been refurbished. I can feel the resistance about 3/4"
down the pedal travel but it has to be pushed much further before there is any real resistance. Something leaking internally or fitted incorrectly? It may be a few weeks before I tackle the job but I'll certainly report on my findings.

Post by **Willie** » Thu Oct 03, 2002 6:13 pm

well of course the pedal should go very hard even if you have to
pump rapidly to get to that point. Yours doesn't so you either
have air in the system or the fluid is squeezing past the piston
seal when you apply pressure. You could prove that to yourself by
pressing hard on the pedal and noting if it slowly goes to the floor?
Willie