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Case 621B XT - NO BRAKES

Odonus

Member
Joined
Mar 10, 2014
Messages
14
Location
Australia
Hi there - new here and hoping for some knowledge sharing

My current project is restoring a 2008 FEL that I have acquired from work. (it has been badly salt corroded by the product it was moving).

It has been sitting dormant for 5 years and I managed to get the engine running and most of the hydraulics. Apparently all run before it was parked.
I do have a 621B schematic manual but only a 621 service manual...

The unit has had numerous hose issues (ie: corroded - blowing off) Now most repaired for testing

My brake pressure light on the computer and the flashing red light near steering column is indicating brake issues
At the wheels - there is no fluid coming from new hoses, and only some from old lines not replaced.
It seems that there is just no fluid pumping to these wheels.

Have had engine running for many minutes and cannot determine why no fluid when I open up any lines. No brake pedal pressure

I am assuming the brake pump (where is this located) is not functioning - or something else

Before I go stripping pipes and hoses, I would like to get information from those here. I have the standard tools, but can arrange to loan items from service persons in this arena if I really had to!!!!

My questions today is to determine the following

Is the brake pump located on RHS in Engine bay?
Does it get an auxiliary feed from Hydraulic pump to boost it (My schematic book shows it - but I do not understand how it works), so I am assuming it should supply some oil to the wheels?

ANy information or assistance would be appreciated

BTW - I am located in Victoria Australia

Note: - At present the unit is parked some 100m from my shed. If I can get around the brake pressure issue - I was hoping to drive it to the shed to commence the restoration. I was thinking of fooling the unit that brake pressure is good - to drive to shed and commence the strip down/repairs. If anyone here can assist in this option, I would be keen to try

Cheers
O
 

Odonus

Member
Joined
Mar 10, 2014
Messages
14
Location
Australia
Traced back lines to pump on rhs of engine.

Will check delivery over the weekend

BTW - I will try and bleed system if I can delivery from pump to the brake accumulator charging valve.

I see it gets its delivery from the reservoir and looks like a return to the other hydraulic flow control relief valve/oil cooler and filter asy.
Looking at the schematic, the brake accumulator charging valve is separate to the two (front/rear) brake accumulator)
Can this be serviced without discharging Nitrogen from the two accumulators?

Would like to tackle this weekend and get ready prior
Any info would be appreciated

O
 

alrman

Senior Member
Joined
Jun 20, 2009
Messages
3,308
Location
QLD Australia
Occupation
Diesel Fitter;Small Business Owner;Cleaner
Welcome to HEF Odonus!
Does seem a little strange - In theory without brake pressure the machine should not move. They need pressure to release the park brake.
You will need to check pressures & hopefully no one has tampered with the electrics.......
 

Odonus

Member
Joined
Mar 10, 2014
Messages
14
Location
Australia
Welcome to HEF Odonus!
Does seem a little strange - In theory without brake pressure the machine should not move. They need pressure to release the park brake.
You will need to check pressures & hopefully no one has tampered with the electrics.......

I will check - but I believe the park brake uses a cable and disk to clamp the tailshaft from spinning.

My thoughts is to chase the hydraulic oil to various sections, but others have told me these machines are prone for brake valve clogging or scoring.

At present - I have NO FLUID going to brakes - but a question I have " Does the brake pressure sensor fault prevent the travel of fluid" to other components

O
 

wrenchweld

Member
Joined
Feb 21, 2014
Messages
15
Location
Fairview Alberta
Occupation
Heavy duty diesel mechanic
May sound simple but if someone put DOT brake fluid in a hydraulic or " mineral oil" oil system it will cause severe damage to the system.
 

Odonus

Member
Joined
Mar 10, 2014
Messages
14
Location
Australia
Nah - its all hydraulic from same reservoir.

Having trouble removing pipes - all corroded - so will need to leave again after fittings loosen up with my trusty rust penetrator.

I took the nut off at the bottom of the break valve and found no oil. After manual pumping the valve I found seated in it - I began to get fluid - so going to test when have some daylight and home from work to play

cheers
O
 
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