A was for Austin, but now B is for Bedford

Ho hum, nothing goes well for PDU . . . 

I went to drive it out of the shed and in a series of hops and shudders it drove out, straight away it felt like a brake issue again.

Jacked up the front wheels, checked brakes, backed brakes off a tad; checked back right wheels where all was fine; and onto the back left - where all was locked solid! 

This would appear to be a bisector/slave cylinder problem. Best part being ease of getting straight to the problem as the slave cylinder is externally mounted onto the backing plate. The problem can be solved without having to remove the brake drum, etc, and I'm happy for small mercies.

Before going too far I tried releasing some brake fluid from the bleed nipple and was able to rotate the wheels easily.    Inside the cab, applied brakes, then back out to find rear locked up once more. Bled a bit more brake fluid, using the handbrake mechanism to push back on the piston, and wheels free once again. I could repeat this a few more times until it cleans the bore out, but with a little more effort I may as well strip it down and check it properly.

Thus my next task will be to remove the slave cylinder, clean up the bore and reassemble. This should be straightforward as the slave cylinders were all (supposedly) rebuilt.    However, NOT this week - tomorrow is Heritage Centre and Friday we're off to Kingston S.E. for S.A. Club Run. 

Meantime I'm still waiting for BSP oil fittings to connect the gauge. Replacement copper pipe acquired at Clare Swap Meet last weekend, along with a spare radiator cap (just in case some low life decides to souvenir the one on B for at the moment!). 

Moderately concerned but not ready to slash wrists yet. 

 

Strange problem. trying to think this through - If the brake fluid came out without someone pushing the pedal it would indicate pressure retention, however as the other wheel was not affected a return valve issue can be ruled out. Weak brake return springs maybe or the bisector wedge catching on something. Does the handbrake release properly, if not it is a mechanical issue, if yes it is hydraulic. Little lumps of silicone/ptfe tape are known to get into funny places and cause mayhem.

I would normally call that a swelled brake hose, but that would usually affect both wheels.
I'm curious to know the outcome.

Jarrod.

asw120 wrote:

I would normally call that a swelled brake hose, but that would usually affect both wheels.
I'm curious to know the outcome.

Jarrod.




yep

And or a blocked air vent on the master cylinder

Paul 
 

Thank you Mrsmackpaul, mammoth and asw120 all will be taken onboard when I get home again next week, along with the last section below from the Bedford K-M-O Workshop Manual:
 

In the meantime, after returning from the Heritage Centre today I settled down for a cuppa with my wife and we watched a Netflix recommendation of an English four part series called ADOLESCENCE.

Check it out, we were hooked in the first five minutes and ended up watching the whole lot in one sitting . . . all four hours of it!  

Okay, home from Kingston S.E. Run, interesting weekend, and a few previously unseen Victorians along for the ride. (Pictures at the end)

B for is back up on axle stands and blocks again, with the front wheels off. LH rear wheel fine, RH rear too fine (bisector not connected properly?!), RH front is dragging a bit, LH front was dragging a lot - hard to rotate wheel. This suggested (to me) that the slave cylinder was working initially but not returning after master cylinder was fixed, so today the slave cylinder was removed, pistons checked and now appear to be working as they should. Brake drum is now back on and wheel turns freely once more. 

I will repeat this with the RH front and then move on to the rear brakes on Friday. Hoses all look great. Once the rear end is sorted I will ensure clearances at the master cylinder activating rod, brake fluid level, and hole is clear (if there is one?). After which I'll check the Clayton-Dewandre servo unit is moving okay and then bleed the brakes for the third time. Don't expect anything in a hurry.  

Which brings me to the Kingston S.E. Run piccies . . .  



  
With a few more following . . . 

S.A. Kingston S.E Run pictures . . .



The last one, following, being my favourite, and what I should have built rather than the O Type Bedford (wash thy mouth out PDU). 

Well done PDU
Really that is a great result for truck, things only go 100% correct on T.V. shows or when someone is dribbling do do out of their mouth

I wonder if it is as simple as the slave cylinders seized up a bit from sitting ?


Paul

Nice mix of truck brands on the run and not being over run by bugs.

Those brakes have been a challenge fir but I'm sure will get it sorted