Massey 7400 series brakes

[jthomsonagri]

Hi, anyone got any ideas why my brake pedal has started pulsing when I apply the brakes. It only does it once warm and not all the time. If I apply the brakes very gently it won't do it and also if I am towing something with trailer brakes it doesn't do it.

 

[masseyman74]

@Cowabunga may have some idea?

 

[Cowabunga]

It almost certainly has something to do with the trailer brake valve actuating pressure to the pipe which dead-ends.
Are you sure it hasn't always done it?

 

[jthomsonagri]

I have only noticed it over the last couple of days. It varies in severity, at times its that bad that it's hard to stop the tractor. Could some dirt have got into the trailer braking valve causing something to stick?

 

[Cowabunga]

I have only noticed it over the last couple of days. It varies in severity, at times its that bad that it's hard to stop the tractor. Could some dirt have got into the trailer braking valve causing something to stick?

I've come across this pulsing before but those times there was no fault, that was just how they were.

Check simple things first. I'd check for any wet patches, because an oil leak might cause this.

 

[davedb]

Sounds like the brake booster playing up?

 

[jthomsonagri]

No visible signs of an oil leak. Now you come to mention the brake booster there is a faint whooshing noise coming from the master cylinders when you push the brake pedals down

 

[mf3085]

Sounds like the accumulator has burst under the cab it sits in the open before vario unit you better check out quick as it can crack the master cyl and that's more £

 

[mtx.jag]

@davidroberts30

 

[Farma Parma]

brakes on my 7499 are useable but nowt like the pedal feel on the 6480
even when hooked up to a trailer which they do work the trailers brakes yet still feel naff compared to the 6480's set up
Dealer checked everything over & thats just how they are.

Yes i know everything from the back of the pedals is totally diff on the 7499 but all the same you would have thought the
whole thing would actually be a step up in quality coming from the FENDT stable but its the other way around.

Motto is try not to use the bloody things.

 

[davidroberts30]

@davidroberts30

mine has just started to do this too

 

[jthomsonagri]

mine has just started to do this too

What are your symptoms? Surely if it was the accumulator it would do it all the time, mine only does it when hot

 

[jthomsonagri]

Had a look on the agco parts site and the only accumulator I can see to do with the brake circuit is part number 3789371M3. From what I can work out it sits in the low pressure supply line to the master cylinders. @mf3085 I take it you have had similar issues before, don't mind buying parts so long as I'm pretty sure they are needed.

 

[davidroberts30]

What are your symptoms? Surely if it was the accumulator it would do it all the time, mine only does it when hot

Feels like the pedal has abs and a noise valve

 

[jthomsonagri]

Exactly the same as mine, had to borrow a tractor for the round baler yesterday as it's undrivable with no trailer brakes plugged in! Going to ring dealer in a min and see if they have an accumulator, hopefully that will sort out.

 

[davidroberts30]

Exactly the same as mine, had to borrow a tractor for the round baler yesterday as it's undrivable with no trailer brakes plugged in! Going to ring dealer in a min and see if they have an accumulator, hopefully that will sort out.

Cheers let us know the price

 

[jthomsonagri]

I think looking online it's about 100 pound

 

[jthomsonagri]

New accumulator is £139 from my local dealer, not to bad but have you seen where it's located on the tractor? Only way I can see of getting to it is lifting the cab Anyone done one before and have any tips please?

 

[rolfy]

New accumulator is £139 from my local dealer, not to bad but have you seen where it's located on the tractor? Only way I can see of getting to it is lifting the cab Anyone done one before and have any tips please?

ll

New accumulator is £139 from my local dealer, not to bad but have you seen where it's located on the tractor? Only way I can see of getting to it is lifting the cab Anyone done one before and have any tips please?

left hand wheel and fuel tank need to be removed to get to it,cab doesnt need to be lifted,its a good time to check the front cab mount rubbers while the fuel tank is out

 

[davidroberts30]

ll

left hand wheel and fuel tank need to be removed to get to it,cab doesnt need to be lifted,its a good time to check the front cab mount rubbers while the fuel tank is out