MJ Brakes

I have been driving my Bedford MJ in the last few weeks and every day the brakes are awful.

No matter how gently I try to apply them, they act like a switch - either 'ON' or 'OFF'.

When I try to apply them, they simply lock up instantly.

The only way to overcome this I have found is to drive round the yard a bit with the brakes applied very lightly so the truck is labouring (as if to 'clean' the brake drums?) and then its okay. However, if left for a few hours, it reverts back to 'ON' or 'OFF'.

Any clues anyone ?

Have you blown the air system out recently?

I have been driving my Bedford MJ in the last few weeks and every day the brakes are awful.

No matter how gently I try to apply them, they act like a switch - either 'ON' or 'OFF'.

When I try to apply them, they simply lock up instantly.

The only way to overcome this I have found is to drive round the yard a bit with the brakes applied very lightly so the truck is labouring (as if to 'clean' the brake drums?) and then its okay. However, if left for a few hours, it reverts back to 'ON' or 'OFF'.

 

Any clues anyone ?

Not at all uncommon on MK/MJ, seems worse when driving slowly or manouvering.

Some of the buses seem to have developed a similar habit latley. Pumping the air out a few times seems to help, and as you say when everything gets warm. Might the very cold weather have caused contaraction of the brake drums?

Some of the buses seem to have developed a similar habit latley. Pumping the air out a few times seems to help, and as you say when everything gets warm. Might the very cold weather have caused contaraction of the brake drums?

I would imagine your buses would be full air, the Bedford is air over hydraulic, so not quite the same. My recollection was that it was not thought of as a repairable fault, just one of those things that happens, bearing mind they used to stand around a lot. About 15 years since I had anything to do with them now...........much prefer the QL anyway :-)

Ask Clive (protruck) - ours were on/off until he adjusted them and now a lot better!

They all seem to have a tendency to be a lot sharper on the brakes than the accelerator (especially with the enormously wide gear ratios on an MJ) but they can be adjusted to improve it a fair bit. When it first came off the low loader the delivery driver nearly put himself through the windscreen!

Stone

I have been driving my Bedford MJ in the last few weeks and every day the brakes are awful.

No matter how gently I try to apply them, they act like a switch - either 'ON' or 'OFF'.

When I try to apply them, they simply lock up instantly.

The only way to overcome this I have found is to drive round the yard a bit with the brakes applied very lightly so the truck is labouring (as if to 'clean' the brake drums?) and then its okay. However, if left for a few hours, it reverts back to 'ON' or 'OFF'.

 

Any clues anyone ?

I have been talking to a friend who was an instucter on MK/MJ's its a common fault and something you will after get used to, at least you will stop.

Al

same on my urals too, on off, no inbetween, I pump the brake pedal rapidly, it give me a semblance of control...

I have shared your experiences, and would comment that adjustment does help, use of vehicle often helps, but caution is a watchword on MJ brakes, they are more aggressive than your average civvy daily driver. Dont neglect to put methyl hydrate in the resevoir for air lines and drain your air tanks on a regular basis ie daily.

My best moment with "grabby" MJ brakes was with bar grip tyres on a narrow mountaineous road in Quebec with a load on in a sudden summer down pour and a plug of a wazack pulled out of a minor road in front of me without looking, I was looking at him the whole time and we never once made eye contact.

Needless to say the truck broke traction and hydroplaned and I did the MJ dance across the road and cursed. My speed was such that in a normally shod vehicle I would have been fine but I neglected to throttle back because of the tyres, my fault.

Shortly after a change of underwear a call was placed to "higher" informing said higher of my dislike for near death experiences and a hearty suggestion to change tyres to a better grip which we have since done.

R

Thanks all.

During the summer when stood for a week or two, I had to 'warm' the brakes by driving round the yard with them on but then she would behave brilliantly and would brake as well and controlled as any car (well, like a morris minor...) but the last week or so she has been nothing but a pig.

I will look at the adjustment tomorrow and also using methyl hydrate.

I drained the tanks down the other day - bit damp but nothing unusual but will do again tomorrow.

I'll let you know how I get on. :-)

Thanks,

DR

Its common with beddies at first.

It was good practice to drive them round the yard to warm them up before going out, the one driver who forgot or didnt know as we set of on excercise, loaded up with squadies, the first time he hit the brakes we all flew to the bulkhead.

He knew after all the foul abuse he got though!

Even when we were brake testing them, we just drove round the parking with foot on brake for a minute, stop's them grabbing.

Otherwise a great vehicle.

Shaun

I have been driving my Bedford MJ in the last few weeks and every day the brakes are awful.

No matter how gently I try to apply them, they act like a switch - either 'ON' or 'OFF'.

When I try to apply them, they simply lock up instantly.

The only way to overcome this I have found is to drive round the yard a bit with the brakes applied very lightly so the truck is labouring (as if to 'clean' the brake drums?) and then its okay. However, if left for a few hours, it reverts back to 'ON' or 'OFF'.

 

Any clues anyone ?

Hello mate,

I own a Bedford MJ and I was also in the Army and I can honestly say I've never driven a Bedford that doesn't try to throw you out of the cab at the first application of the brakes!

The brakes will always grab on a Bedford, that's just the way they are. The best way to overcome it is for some braking at low speeds. I bought my truck two months after it had been through ABRO, where it had new brake linings, wheel bearings, new brake fluid and brake wheel cylinders, so they are as good as they will ever be, but they still grab when cold.

The reason they are grabbing a few hours after you have shut her down is purely because it's so cold.

When I drive mine they are lethal on the first few applications and I try to only just breath on them to start with. They are fine after that. It does help having a heavy box on the back of mine. Is yours a Cargo or Flat bed?

Also have you checked the setting of the Load Sensing Valve?

By the way. I am using 99.9% Methanol in my brake antifreeze system. You have to be carefull when buying this as some Methanol products contain water. I go to a chemical factory and buy 99.9% pure Methanol that has no water content. Expensive though.

Here are my tips.

Fire up truck and blow the air out of the system using the foot brake a few times so any moisture has been expelled and the valves are working OK.

Drive truck slowly and keep applying the brakes until she no longer tries to kill you.

Get some weight on it.

Drive, drive, drive!!!:-D

Sounds daft to be complaining that the brakes are TO good! :-D

Sounds daft to be complaining that the brakes are TO good! :-D

Then come and drive it first thing...:cool2:

I will scrape you off the windscreen after breakfast.:nut:

I think if i get a day next week I will get her in the workshop and have the drums off.

I agree that Mk/MJ's are bad on the brakes and I have always been able to 'warm' mine in the morning but just lately she has been horrid.

Its a flatbed with an Atlas crane, ex-RAF. Lovely truck and it runs like a sewing machine, well, a sewing machine with sharp brakes !

Number One Son's Land Rover is similar.:-D Problem is when you get in something else **** is this one going to stop!

So your MJ has you in Stiches then?

Sounds daft to be complaining that the brakes are TO good! :-D

Yeah, funny that. We seem to moan about anything, lol. I don't complain about my brakes. They are only sharp for the first few applications and then settle down, but they are still very good brakes even when warm. As mine weighs 7.9 tonnes without the 12x12, poles, bench seats, tables and missus I'm glad they are good!!

As my old Mentor Howard used to say , frequently 'A Bugger if they don't go, a disaster if they don't stop!':-D

When the brakes are warm they are simply brilliant. You can feather them nicely.