Marshall 802 brakes grab

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mmoore01
Posts: 4
Joined: Thu Oct 15, 2020 3:43 am
Ireland

Marshall 802 brakes grab

Post by mmoore01 » Thu Oct 15, 2020 8:58 pm

Hi all,
My marshall 802 brakes grab/snap on quite suddenly near end of pedal stroke. I bled the brakes, jacked up wheels and adjusted brakes. I thought problem was solved and had a nice gradual brake. It snapped on again next morning. I only have tractor a year and have noticed that the mat under the brake master cylinders looks damp when i got it. Could i have back pressure leakage coming back through the master seals?

Tks for help
Mike



Rick Cobley
Senior Member
Posts: 364
Joined: Fri Mar 30, 2018 9:32 pm
Location: Leicestershire, UK
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Great Britain

Re: Marshall 802 brakes grab

Post by Rick Cobley » Thu Oct 15, 2020 10:59 pm

Hi, I have no direct experience with grabbing wet brakes, but my understanding is that this happens when the plates become worn and can be cured by slipping in an extra plate to take up the ware. Talk to Charnleys about this 01254854103.

https://www.charnleys.com/part/leyland_ ... ction-disc

Regards Rick Cobley

mmoore01
Posts: 4
Joined: Thu Oct 15, 2020 3:43 am
Ireland

Re: Marshall 802 brakes grab

Post by mmoore01 » Thu Oct 15, 2020 11:54 pm

Tks Rick

DAL PZ
Posts: 104
Joined: Mon Apr 09, 2018 10:39 am

Re: Marshall 802 brakes grab

Post by DAL PZ » Sat Oct 17, 2020 12:30 pm

My 802 grabs intermittently I should probably add a couple of discs as Rick says, its a known occurrence & the recognised solution but though its not hard or difficult I just can't face manhandling the rear wheels off & on. But I have developed a driving technique," of using the brakes, that makes the "problem" bearable & livable with.
When I need to apply the brakes I "lightly" rest my foot on the pedal & hold for a couple of seconds until I "feel" the brakes just take up & begin to bite then I gradually progressively press harder as necessary to stop in a controlled fashion.
It requires anticipation & is no use for emergency stops but in that situation if you stamp hard you're probably going to lock the wheels anyway with or without the problem!
If I apply heavy pressure straight away the brakes will lock up but releasing the pressure momentarily & then reapplying it (cadence braking) usually keeps us straight & safely stopped.
I don't do high speed heavy load road work anyway but it works for me -try it.
PS there was a "ask the Experts" feature on it Page 109 of May 2018 edition of Classic Tractor. Evidently the cause is that "because of wear in the discs & expander movement gets sharper as the balls roll up the expander ramps."

Dixie normous
Posts: 10
Joined: Mon Apr 01, 2019 9:13 pm
Great Britain

Re: Marshall 802 brakes grab

Post by Dixie normous » Thu Oct 29, 2020 8:18 pm

I have also known wet brakes grab whet the wrong oil was put in the back end, it has to have an "anti-squark" oil, such as UTTO

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