Dave’s long-term Lil’Bugga Buggy Build

Ahh, many a true word... seems I've missed a couple of updates!

 

More parts have been amassed! :lol:

A complete set of parts for the front front axle rebuild...

4 kingpin bearings
2 Axle Seals
2 Swivel Ball Seals
King Pin Bolts and Axle Seal Bolts
Radius Arm Bolts
4 Track Rod Ends for the Steering Bars
Brake Pads
And axle ball 10mm steel gussets from he who can not be named on this forum but his initials are 'RW'

The plan is to narrow and rebuild the front front axle first whilst meanwhile saving for another set of parts to build the rear front axle, hence the 26 spline side gears shown above...

Obsessed? Moi? :evil:

Not much time at the moment, one of our staff is off this week and next, so rather than calling one of the other staff in I thought I'd do their hours myself, and that way I'll have enough for the tyres at the end of the month... I've already agreed with my mate in the tyre bay that they'll get sent straight to him so the wife doesn't see them

Meanwhile, plenty of time stood at the till, thinking and Googling... this week "fiddle brakes" (also known as cutting / steering brakes) being able to brake either side of the rear ('front') axle independently with levers to aid steering in tight areas, i.e. brake the left rear wheel and the (open) rear diff will transfer power to the right wheel and make the buggy steer tighter, especially when aided by the proposed rear steer too (hence also using a front axle on the rear).

I looked at aftermarket systems (Llama4x4 and HM4x4 for instance) but they seem to offer lever systems to brake another calliper fitted to each rear disk brake, where as I wanted to use the existing rear callipers, so that I can press the brake pedal and get four wheel braking, or pull a lever to brake just one rear wheel...

More Googling then, and read lots of forum posts referring to...

 

Hillman Imp master cylinders, these (usually) have the feeder tank plumbed to the right hand port, and when the brake is applied the piston is pushed in, the inout valve is closed off (by the passing piston) and the brake fluid is squeezed through the left port to push the brake disk pistons on... so in my scenario this will (apparently!) then work as a pass through - So if I use the standard Jimny brake master cylinder with it's fluid reservoir on top, through the standard brake assembly, the brakes will all (four) work as intended, as the Imp master cylinders will be "open". Then if I want to use the fiddle brakes, I pull on the (to be manufactured) long handle and that will apply fluid just to the intended wheel...

As you can see, these were only £31 each (two required) and some fabrication to get them working, where as aftermarket ones are around £200, and don't appear to work as I wish...

I may still have to work out a handbrake facility too?...

The thinking and Googling continues then...  
 

:lol: There's timing! The postie just delivered them..

 

Even better! They've come with different / better ends on the piston rods ideal to connect to the handles -

 

Like these (Llama4x4) ones...

The piston does not seem to cutoff the input port as said above though... but that'll work fine in my proposed system anyways...

From looking at the complicated schematic -

 

and thinking about it some more... the piston(s) must shut off the input port, otherwise the brake fluid header tank would get pressurised...?
 

Yes, I think this the way these brake cylinders work. Otherwise it would be impossible to build up sufficient pressure because the air in the header tank would just compress (a little).

So from what I understand, you plan to align the breaking cylinders in series. I would think this could work. In this case the second cylinder has the full braking pressure while not pressed at all. I am not sure that a usual break cylinder is designed for this regarding sealing or pushing out of the actuator.

You might avoid this, if you design them in parallel with (at least) in total 4 stop valves.