Author Topic: oil on the front brakes!  (Read 549 times)

Offline Sam C

  • A's Best Friend
  • ***
  • Join Date: May 2015
  • Posts: 56
  • Karma: 0
oil on the front brakes!
« on: 26.06. 2015 17:10 »
Gents

For those that don't know, I'm very new. I did a little intro. a couple of months back.

I have an A10, and I'm doing my direct access bike test at the moment. The A10 was a family bike, and now it's mine.

Full tests all happen this coming week so I'm hopefully not far from being able to ride it. However, in the month's I've had it in storage I've noticed that apart from the predicted, presumably very normal, oil leakage from somewhere or other... I seem to have a small amount dripping form the forks and onto the front brake (like the odd drop: nothing major).

My question is twofold:

(a) Am I right in thinking this is something that is just automatically a problem. I would say it certainly is with disk brakes but I wondered if drum brakes were basically a sealed unit so not such an issue.

(b) Should I just go and buy certain seals on the assumption it will definitely be them i.e. it's 'always them'. Or could it be more complicated i.e. 'take it apart first then see'. Or even better, could it be as simple as putting some PTFE tape on a thread somewhere.

Thanks for any help you can give.

cheers

Sam

Online Triton Thrasher

  • Scotland
  • Wise & Enlightened
  • *
  • Join Date: Feb 2009
  • Posts: 1504
  • Karma: 20
Re: oil on the front brakes!
« Reply #1 on: 26.06. 2015 17:59 »
If oil gets onto the linings and drum interior surface, the brake won't work.

An oil leak from the forks is a bike in dangerous condition and they won't let you sit your test on it.

I have no idea whether the leak is via seals, threads, drain plugs, overfilling, or whatever.  Sorry.

Online morris

  • Wise & Enlightened
  • *
  • Join Date: Aug 2012
  • Posts: 1595
  • Karma: 24
  • Antwerp, Belgium
Re: oil on the front brakes!
« Reply #2 on: 26.06. 2015 23:58 »
I think your best bet would be to take the forks out, unscrew the seal holders, change the seals and renew the thread sealing of the seal holders. Use a good quality pipe sealant. PFTE tape is rubbish (but that's personal opinion)
The drain plugs at the bottom also have a tendency to leak if not sealed well. I use folded copper sealing rings on them.
Often there's a lot of muck in the bottom of the sliders. Draining and filling up with the "correct" amount of oil actually overfills them. The oil then is pushed past the seals, overflows the seal holders and runs down the outside of the fork leg. This can be seen after a ride when you unscrew the filling caps and have a peek down the forks. If you see oil sitting on top of the seals, it's no good.
If well done, forks can be made leak free.
'58 BSA A 10 SA
'52 BSA A 10 Plunger
'55 MORRIS ISIS
The world looks better from a motorbike
Belgium

Offline Rocket Racer

  • Wise & Enlightened
  • *
  • Join Date: Jun 2009
  • Posts: 1430
  • Karma: 16
  • A kiwi with a racing A10 rig and too many projects
    • NZ Classic Sidecar Racing
Re: oil on the front brakes!
« Reply #3 on: 29.06. 2015 10:10 »
. I seem to have a small amount dripping form the forks and onto the front brake (like the odd drop: nothing major).


Sam,
might be helpful to post a picture of the oil on the brake, if its getting into the brake hub and onto the pads obviously very bad!

Leaking fork seals would fail what we call a Warrant of Fitness over here and force us off the road until remedied.
If just the odd drip a regular wipe over is an option but would be worth checking the fork oil levels as a lack of oil won't assist your road holding as the bike will lack damping.
If overfilled they also tend to leak and I recall mixed oil volumes mentioned in various literature. Also pays not to run light fork oils.

Assuming its got a leaking seal the worry is corrosion on the fork stanchions from moisture in the sliders. If pitted they quickly eat seals and need replacing,
Could just be a matter of old seals, a fairly cheap and easy fix if everything else is in good order.
If pulling off the legs you will need a fork seal removal tool, usually made from an old pit of scrap pipe so you don't damage the seal holders

Tim

A good rider periodically checks all nuts and bolts with a spanner to see that they are tight - Instruction Manual for BSA B series, p46, para 2.
New Zealand

Online cyclobutch

  • Wise & Enlightened
  • *
  • Join Date: Aug 2010
  • Posts: 1508
  • Karma: 14
Re: oil on the front brakes!
« Reply #4 on: 29.06. 2015 11:41 »
I think it unlikely that the oil will have got to the brake linings. Mine have leaked from the drain plugs in the past and that never found its way into the drum. Sure way to know is to pull the wheel out and look of course. I guess you’ve not ridden it far yet, but don’t be perturbed when you do if the brake is none too good. That’s kind of normal anyway. If the bike is pre 60 then you’ll not need an MOT so these decisions are pretty much between you and your maker. I’m not convinced that with std fork internals the oil does that much beyond lubrication anyway – but then maybe it has now all fallen out of mine.
Various, including ...
'58 Iron Head Flash Bitza


Offline Sam C

  • A's Best Friend
  • ***
  • Join Date: May 2015
  • Posts: 56
  • Karma: 0
Re: oil on the front brakes!
« Reply #5 on: 29.06. 2015 14:40 »
All

I really appreciate the advice and help. Thanks for that.

I've taken a closer look, and got a second opinion from an experienced biker neighbor who has an array of old bikes that he maintains himself.

We're fairly sure the oil is leaking from the drain plugs at the bottom. The plan is to drain the oil and refill and refit the drain plugs with some sort of sealant on the threads, maybe even silicon sealant. It's a very small amount of oil and I think it's related to the hotter weather we've had just recently: my garage gets pretty boiling when we get good weather, so I think it's the change in viscosity. I'm losing more oil than normal out the bottom of the bike too - not quite worked out where from: just treating that one as 'normal for a 60 year old BSA'!

To the extent that oil had dripped onto the drum, it was on the left hand side and seemed to have dripped onto the outside i.e. the case and that's about it. I will clean all this up and be very careful indeed on my initial outings (which I would have had to have been anyway - I'm dreading the possibility of dropping this bike, as a new rider, after all this work and money!).

Thanks again all. If it's not what we think then all this advice will be really helpful when I start pulling the forks apart.

Out of interest what oil should I be looking for in UK shops that would be suitable for the forks?

Cheers

Sam





Online Greybeard

  • Jack of all trades; master of none.
  • Wise & Enlightened
  • *
  • Join Date: Feb 2011
  • Posts: 6176
  • Karma: 35
Re: oil on the front brakes!
« Reply #6 on: 29.06. 2015 15:23 »
I'm dreading the possibility of dropping this bike, as a new rider, after all this work and money!).

When I got on my newly restored Golden Flash three years ago I hadn't ridden a motorbike for thirty years. I was rather nervous and I'm still careful. I dread dropping her and buggering up the finish! The A10 must be one of the kindest motorcycles to ride; sure they are heavy but the centre of gravity is low, likewise the saddle, particularly on the plunger models is low. The low speed torque is very nice; reminds me of a diesel engine; the standard tune allows the bike to plod along at low speed in top gear. The brakes if set up properly are not too bad; not up to modern disk brake standard of course but that means you have to be a better rider, leaving generous stopping distance and anticipating when to stop; nothing wrong with that! If you don't fit indicators the fact that you need to stick your hand out means even more anticipation.

Offline Rocket Racer

  • Wise & Enlightened
  • *
  • Join Date: Jun 2009
  • Posts: 1430
  • Karma: 16
  • A kiwi with a racing A10 rig and too many projects
    • NZ Classic Sidecar Racing
Re: oil on the front brakes!
« Reply #7 on: 29.06. 2015 21:55 »
I'm losing more oil than normal out the bottom of the bike too - not quite worked out where from: just treating that one as 'normal for a 60 year old BSA'!

Out of interest what oil should I be looking for in UK shops that would be suitable for the forks?

Cheers

Sam
The book says SAE 20, certainly nothing lighter for the primitive damping.
and oil leaks go with the territory, a bit of vigilance might help you track them down and correct them, but bikes that have been stored typically leak. If really bad pays to have identified whats leaking so you can put more in the right place.
In my youth I had a knackered c11 bitsa that leaked chronically but was reliable as. It was so bad service station attendants used to comment that oil was pouring out as I added more  *dunno*
Use it and enjoy.
A good rider periodically checks all nuts and bolts with a spanner to see that they are tight - Instruction Manual for BSA B series, p46, para 2.
New Zealand

Offline duTch

  • Ricketty Rocketty Golden Flashback
  • Wise & Enlightened
  • *
  • Join Date: Oct 2011
  • Posts: 4540
  • Karma: 41
Re: oil on the front brakes!
« Reply #8 on: 29.06. 2015 23:26 »

 I have a Conical front on mine, and due to being more modern and 'Hi-Tech',  I figured it must take 'fork oil', so just did a check and the specs for them say ATF  *doh*....seems to be a universal usage, even the guy at the Jack shop said to use it in a small floor jack...but there's also different types of ATF too, but maybe not turn this into an "oil thread'...
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
Australia