Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing brake failure

Slightly more interesting drive home from work today than anticipated. On pushing the brake pedal in my usual gentle way, there was very little resistance, the pedal went all the way to the end of its travel, and there wasn't much in the way of slowing down. All rather alarming since I had committed to the highway on-ramp at the point I noticed anything wrong. Thankfully traffic was fairly light and I managed to drive home very defensively, making sure I put pressure on the pedal to let cars behind know I was slowing down, but using engine braking and a bit of help from the handbrake to get me home safely.

I didn't have time this evening for a proper investigation, but first findings are that, as suspected, the brake fluid reservoir is pretty much completely dry; I can't see any obvious evidence of fluid loss (wet surfaces etc) at any one point, so I'm preparing to take things to pieces until I find the culprit. I suspect that it'll be a seal on one of the wheel cylinders, but it's possible I suppose that the master cylinder is gone. The car's been running really sweetly this summer, and has mostly been in the dry, but did get an absolute drenching as I got caught in a torrential downpour of a thunderstorm last Sunday afternoon. I can't see, though, that that would have any bearing on the brake failure.

I suppose I ought to dismantle and examine everything to be on the safe side, but my eldest (who is gutted that we'll have to take the tin-top when I deliver him to a week's interprovincial music camp on Saturday, it was to have been a lovely drive about 3-4 hours north of Toronto in the Mog) suggested that I should refill the reservoir, park the car on a load of old newspapers, station an observer at each corner, and pump the pedal until somebody sees where it's all pissing out from. Is that a completely off-the-wall suggestion (aside from being not terribly environmentally responsible, of course?

In the collective wisdom of the TM populace, what's the first place I should look?

I foresee, rather than a season of mists and mellow fruitfulness, that my autumn is going to consist of evenings spent on my back on the garage floor... not quite the same romantic ring to it! Everything's a bit mucky under there - serves me right, I guess, for paying more attention to driving than to cleaning. Perhaps this will end up being a bit of a salutary lesson and the underneath bits will have a bit more attention from the bucket and sponge in future!

Doug,
To be perfectly frank;
The first place you should look is to your own conscience!
With due diligence, this should never happen.

Bit harsh. Moggo!
A lot members must just jump into their Morgan without checking !

If there are no obvious signs of a leak then I would have thought that the servo has eaten the fluid. White smoke from the exhaust would confirm that.
Cheers
John

Rear brake cylinders are the most likely source of the problem. Dried crap on the insides of wheels may well absorb fluid before it reaches the ground.

Doug, good that you did not find out you had an issue the HARD way.... brake failure can be a heart stopper... been there done that ...!!! That you have lost fluid kinda takes master cylinder out of the mix, unless anything is visible by way of fluid around it... If you have a servo (?) I have known fluid to leak into them, which can be picked up on the dip stick as dots of fluid, a bit like water in the oil. My bet would be on a wheel cylinder or less likely calliper piston... though at the age of your car corrosion on brake lines could perhaps be an issue. I would start with the rear brake cylinders.. if they have leaked you might also need replacement brake shoes as they will be contaminated... Though I have in the past burned the oil out of the shoes with a blow torch as a temporary measure when replacements were not to hand.... but then I can be a bit stone age mechanically at times (-:

Good luck.

Wow! That must have been a shock! Could have turned nasty very quickly.

Thank goodness you are still here to tell us about it. I think it must have been "brown trouser time" Having had problems with the rear wheel cylinders on my car which is only 4 years old, I think I would start there and gradually work back towards the front !!!

A 1985 4/4 will have the split circuit master cylinder , these has a central seal which can (and does) wear which leads to a very soft pedal and can occur suddenly. However this would not account for the fluid loss , so I would look elsewhere.

Again a 4/4 of that era would not have a servo as standard , so unless a previous owner has fitted one , I would discount that.

The question is when did you last check the fluid , ie: is it one sudden loss , or a gradual seeping away? That would point the investigation into 2 different paths.

If the former I would be looking for a brake pipe that is rubbing on the chassis , or a failed flexible hose perhaps, the fluid loss may not be evident under the car as it might be "held" on a chassis rail.

If the latter then I would regard the rear wheel cylinders as the likely culprit. As others have commented it is possible that the fluid seepage has been contained within the drum, and is not evident on the floor or under the car , but you need to pull the drums off and investigate.

I know that feeling well. As the pedal goes to the floor it seems that the car actually accelerates because your body and mind are set for a deceleration that doesn't happen. I still recall every detail even though it was now 50 years ago

In my case it was a burst flexible brake line. I came over the crest of a hill on a 3 lane (each way) highway to find a red light at a pedestrian crossing, 3 cars, one in each lane, stationary, and a postman on the footpath waiting to cross. I put my foot on the pedal and it suddenly went to the floor. I then yanked on the totally ineffective hand brake. First I went up on the footpath frantically blowing the horn but the postman froze to the spot with his mouth open in surprise. I went back onto the road and aimed for the space between the traffic light pole, a heavy wooden telegraph pole, and the nearest car. I sideswiped the Telegraph pole and by some miracle missed the car. I eventually pulled up in a steep driveway of a service station. The slightly rattled owner of the car I had narrowly missed came to see if I was OK and told me he had only taken delivery of the car the day before.

I don't think I will ever forget the look on the face of that postman!