Uprating the front disc brakes

[AndyLala]

Can't remember now, but have you got braided flexible hoses Andy? If you replace all the rubber lines with these, they often make the brake feel less spongy and the rubber bulges under heavy braking, but the braided lines tend to hold the rubber inner the right shape.

Also what pads to have in, maybe try some genuine Toy pads and shoes
.

Yup, got braided extended lines... and genuine pads... fluid refreshed under 12 months ago... for last MOT...
Obviously the proportion front to rear is right (about 50%), just want them to be a little more responsive...

[Guest]

Can't remember now, but have you got braided flexible hoses Andy? If you replace all the rubber lines with these, they often make the brake feel less spongy and the rubber bulges under heavy braking, but the braided lines tend to hold the rubber inner the right shape.

Also what pads to have in, maybe try some genuine Toy pads and shoes
.

Also drain out and replace the brake fluid. Over time it absorbs water and becomes less efficient. New brake fluid will increase the braking efficiency dramatically.

[Chillitt]

as an associated question, coulpe of times i've gone for the brakes, and the pedal feels solid, and no brakes (yikes!) let off and try again, and its all working normally.any ideas?

[BUSHWHACKER]

Maybe a vacuum problem.

[laser_jock99]

Maybe a vacuum problem.

Or possibly a problem with load sensing valve above the rear axle. I gather it's function is to send more braking to the rear end if it's fully loaded. Not sure how you can test if it's working right though.

[ja1983]

Or possibly a problem with load sensing valve above the rear axle. I gather it's function is to send more braking to the rear end if it's fully loaded. Not sure how you can test if it's working right though.

if the vehicle has been lifted, the load sensor will "think" theres less weight in the back, and the rear brakes will be backed off, i remeber owning a saxo VTR (stupid and wreckless youth, yes i am ashamed!) and having it lowered (oposite effect - "thinks " more weight therfore rear brakes increased)which resulted in locking up the ass end and sliding up to traffic in a generally sideways fashion!

my p/u has been lifted but i guess the valve has been adjusted as on wet roads i can lock all 4 wheels on an empty load! (scares the **** outta passengers!)

not sure how you would test it, but needs to be balanced or will result in a lot of stress on the front brakes (wear and possibly failure)

Chillit : sounds not so good! possibly sticking cylinders/sliders? would certainly get it looked at asap! possibly an air lock in the fluid..?

[AndyLala]

The load sensing valve on the rear axle is to adjust it back to 50% of the front brakes... So mine is correct... Just wanted a little more oomph... oh well back to the drawing board... Didn't someone mention that Supra's have the same brakes.... and AP racing make upgrades for that... Hmmm, Supra uprated brakes all round, should stopp it nicely...

[marky.b]

hope they do, I don't like my brakes but then I am running 35" tyres.

[truckarms]

Andylala if you can find out about the supra option I would be interested, that would be a nice mod to add to the list, I was thinking of discs all round due to all the extra weight I want to stick on the truck but a complete upgrade would be nice.
Let us know how your research goes.
Cheers
chris

[wibblywobbly]

Bit too spongy for my liking

Just a word of warning for anyone who thinks that riding around in a truck with dodgy brakes will be 'ok' and that they will fix them 'one day'.

My other pastime is two wheels. On the 8 August 2004 I was out riding with a group of friends. Two of us in the group were ascending a long 3 lane hill in Wiltshire, we had right of way and the centre lane was empty ahead of us.

Over the brow of the hill came a Frontera not going excessively quickly. It came down the hill in the centre lane but wasn't a danger to us....until it realised that a car was stopped in the kerbside downhill lane waiting to turn right into a farm.

What happened next took 3 seconds from beginning to end. The Frontera driver pulled back into the downhill queue, then lurched back out sideways, and backwards after hitting the car in front. It stopped totally blocking the centre lane. We were now in a steel lined cul de sac. It was 50 yards away from my friend who was doing 70mph, and 100 yards away from me.

I will spare the details, but what happened next was carnage beyond belief. I am still having therapy. I am only alive because I have been riding bikes for 30 years and knew what to do.

What caused it? They had bought the Frontera and thought the brakes were a bit spongy. They took it to a garage, where a new master cylinder was fitted, but what the garage did not do was check the calipers. They were seized.

If you only knew the lengths that the police go to in order to secure a 'death by dangerous driving' conviction, plus all of the associated convictions, each and every one of us would never again venture out with anything other than perfect brakes. Believe me, they leave no stone unturned and are still pursuing the case against the driver, and her partner, and the garage.

No conviction will ever bring my mate back, or give a dad back to his two sons.

Me? I always have my brakes serviced by a reputable garage, on a 'fix anything that needs fixing' basis. It's very cheap insurance.

Remember that the Surf is a 2 ton truck with a high centre of gravity and basic suspension. When it all goes pear shaped you have little chance or recovering the situation and you don't get a letter 2 days in advance warning you of an accident.

Hope this helps someone.

Rob G

[AndyLala]

After some considerable smooching around the intermenet... this is what I have found so far.

Quite a few of our US couzinz have been upgrading their Master Cylinders to FJ-80 master cylinders because it has a 1" (25mm) bore... somewhat larger than our current item on the Surf.

And that is fairly substantial, and will allow you to add a read disc brake kit. (http://allprooffroad.com/index.php?option=content&task= view&id=33 ) I've got a part number somewhere, daren't ask the price at the local dealers...

47201-60580 Cylinder Sub-Assy, Brake Master for a FZJ80 aug 92 - may 94

Another option which I have just stumbled on... A 1 ton GM 4WD Brake Cylinder.. this has come from some of the more obscure buggy builders in the US. Apparently along with the rear Brake cylinders for drums from the Colorado's, again larger bore, along with the master cylinder, or discs on the rear... you get the idea. Larger tyres, more weight, etc...

http://www.rockstomper.com

<Quote>

GM Master to Toyota Booster Swap Kit


The master cylinder you'll need to stop bigger brakes.
Swapped on rear disc brakes? Maybe a Dana 44 or Dana 60 front axle? Got a really low pedal in your Toyota? Here's the fix!

We started with a Toyota minitruck booster--a good, reliable power booster, but when you put bigger brakes on a minitruck, the master itself just doesn't move enough fluid.
We looked at some of the other master cylinder swap options. There are plenty out there--V6 truck, turbo truck, FJ, etc., but none were up to the task of fullsize truck brakes, especially not fullsize truck four-wheel-disc brakes.
So we looked to the fullsize truck itself--and with a little adapter work, we planted the master cylinder off of a one-ton 4WD GM truck, onto the Toyota booster. A fullsize truck master, to stop fullsize truck brakes, with oversize wheels and tires. And a direct bolt-on onto the Toyota booster, with our adapter.
Fits Toyota minitruck, 4Runner, most Land Cruisers with power brakes, etc.
Includes master cylinder, adapter assembly, and bolts. Plumbing adapters are required, and are not included. This product will require some replumbing work to the brake system.
Because the GM master cover does not have a float switch, this part disables the brakefluid-level warning light.
Complete assembly, $95 plus shipping. Includes master, CNC-cut adapter plate assembly, and bolts. Not sold without master cylinder.

</Quote>

Anyone care to discuss...?