Brake pedal slow return

[Graeme]

The brake pedal no longer returns quickly on my 9/84 that gets almost no use, being a backup vehicle only. Brakes still work well. I suspect a booster problem. Rego is due again so need to fix it promptly.
Suggestions?
TIA

[abaddonxi]

How long since fluid change?

Simon

[350RRC]

Try some spray lubricant on the pedal bush up in the footwell. It's bronze and would tend to seize up with lack of use. You'll need to use the skinny extension tube in the spray button.

cheers, DL

[Graeme]

Thanks for the replies.

I cannot remember if I've ever changed the fluid, but certainly not in the last 15 years. It's been almost unused in the last 8 years. As the brakes themselves work fine, I assume there's nothing wrong with the m/c but perhaps incorrectly though.

I don't recall the pedal feeling stiff but will check it. It feels as though a valve isn't letting the air back into the front of the diaphragm quickly enough with the pedal released or the internal return spring has broken. Either way it looks like an overhaul of the booster is req'd, if that's possible. Maybe the mud wasps have blocked a vent! I'll unplug the vacuum line and see what happens.

[350RRC]

Hi,

It won't be the fluid causing this, but I'd change it anyway if it's that old. There is a rod from the booster that only goes into a cone in the first primary piston in the MC, i.e. even if the MC was faulty the pedal should spring back.

I would be doing the simple (CHEAP) things first........ lube the pedal bush as previously posted, then if you have no joy have a look at the spring on the brake pedal up in the wheel well. Could possibly be broken.

If you PM me your email address I can send a pdf of the workshop brake manual, you'll need broadband though because it's about 5meg.

cheers, DL

[DRanged]

It,ll be the spring on the pedal pivot shaft that has failed. Really fun job to change:mad:. My 85 did the same thing.

Justin

[Graeme]

I have the booster apart as it was neither the m/c (unbolted) nor the pedal/spring. The rubber seal that allows air back in past the pedal rod was gunked-up as the filter pad around the rod had deteriorated. I'll get some rubber lubricant tomorrow and put it back together with new o-rings and check that/if it works properly before refitting it.

Thanks for the suggestions and offers. I have a workshop manual from my '76 days and RAVE for the D2, so between the 2 I've got it covered.