? for the experts (Dan) (2 Viewers)

[TiredIronGRB]

There's two WC per wheel on the front and one per wheel on the rear, the front brakes catch really good it's the rear that is lacking. You would think it would be the other way around.

Dan has my back, you better watch out (you know he has lots of weapons and know how to use them). later robbie

Me too

 

[fzj80kidpen]

Looks like a Dan vs TiredIron BIG GUN SHOWDOWN.
TiredIron is that your Christmas Tree trimmer?

 

[powderpig]

I would guess that he does not have a weapon that big, but knowing him he may have some resources.

If you say the front works fine but the rear do not. Two things are 1. loose the rear proporining valve and 2. install a fixed adjustable one and see how this does first. If you need more then work with a bigger MC. Then I would look at what volvo (piston bore x length)design for a MC spec wise to see what you can then come up with in the toyota world that is a close match. good luck robbie

 

[TiredIronGRB]

Thanks Robbie, I was wondering if removing the valve would help. Is there a plug that will work to block where the line for the valve comes out of the front brake tee?

 

[powderpig]

I have not done this mod, so do not really know. Some in the hardcore corner may know. I would guess that with the set up you have you may need to go to a fixed adjustable valve to get more to the rear. As a experement you could adjust the stock one some or rig a way to tie the rod to the frame(take it from the axle and mount it at different distance) at certain distances to simulate different loads which would then give you more line pressure to the rear brakes.
I do not know if there are different types of adjustable ones on the market that would have the return(I would think so). Any how good luck robbie

 

[IdahoDoug]

Before messing with a new MC, I'd definitely work with the proportioning valve a bit until you're either satisfied or cannot get enough power to the rear.

Here's what I'd do: Max out the proportioning valve by putting the valve arm in the position that the rear axle is fully laden on a stock truck. Then drive it around a bit. If you can clearly get TOO much braking at the rear then you've just learned you already have the gear on the truck to make it go too far and your task is now to adjust it away from the rear in increments until you've got the balance you like. At this point you can then assess the balanced braking as to whether you can live with the amount of TOTAL braking force to decide if a further mod seeking greater power is needed.

It's worth noting that the larger tires reduce available braking power in direct proportion to the factory tire diameter/the new tire diameter. I doubt I'm telling you anything new here, but big tire rigs simply don't stop as well due to this simple physics.

A bit more description of the braking issue at that point (once adjusted) would help zero in on suggestions. ie the braking force is fine but takes too much pedal travel to get there, a larger MC bore would move more fluid for the same stroke to engage the long travel of drum shoes (vs disc pads). OTOH if the pedal travel is fine but not enough power then the solution will be a bit more difficult.

DougM

 

[cruiserdan]

There's two WC per wheel on the front and one per wheel on the rear, the front brakes catch really good it's the rear that is lacking. You would think it would be the other way around.



Me too

Me thinks that the .30 caliber AP stuff will bounce right off that one....

May chip the finish a bit tho.......;p

 

[RavenTai]

I would think that if you wanted higher brake fluid pressure you would want a smaller bore giving more hydraulic advantage not a larger one, a smaller bore would create a higher pressure in the fluid for any given force applied to the piston, and of course there is no free lunch the pedal travel will increase.

if you wanted to move more fluid volume at a lower pressure then the bigger piston would help.

Your front drums pistons probably don’t have near the piston surface area of the stock setup