which Wilwood prop valve should I use?

[ctxj93]

Not sure if this is the right spot, but Ididn't think it warranted a new post. When deleting the distribution block and load sensing valve and also going to the 96 master cyl/booster, which is the correct wilwood prop valve to use?

 

https://www.summitracing.com/parts/wil-260-8419

 

Or

 

https://www.summitracing.com/parts/wil-260-10922?rrec=true

[Pete M]

On 2/26/2021 at 8:42 AM, ctxj93 said:

Not sure if this is the right spot, but I didn't think it warranted a new post. When deleting the distribution block and load sensing valve and also going to the 96 master cyl/booster, which is the correct wilwood prop valve to use?

 

https://www.summitracing.com/parts/wil-260-8419

 

Or

 

https://www.summitracing.com/parts/wil-260-10922?rrec=true

 

more eyeballs check the Tech section so I moved it over for you  

[ghetdjc320]

This one:  https://www.summitracing.com/parts/wil-260-11179

 

you can also use the wilwood bracket which comes in either a left or right hand bracket configuration. That’s what I run and it works great. I think my build thread has the pics

[ctxj93]

8 hours ago, Pete M said:

 

more eyeballs check the Tech section so I moved it over for you  

Thanks Pete!

 

2 hours ago, ghetdjc320 said:

This one:  https://www.summitracing.com/parts/wil-260-11179

 

you can also use the wilwood bracket which comes in either a left or right hand bracket configuration. That’s what I run and it works great. I think my build thread has the pics

 I was just planning on running a single inlet/outlet prop valve for the rear brakes and letting the fronts have full pressure with using a tee. Unless there's a reason not to? 

 

I had found guys in previous threads using the first valve I linked to. I wasn't sure if there was a purpose to using the 1/8 npt fittings instead of the 3/8×24. I'm going to run that line right back to the hose for the rear brakes which  I understand is also 3/8×24. 

[ghetdjc320]

1 hour ago, ctxj93 said:

Thanks Pete!

 

 I was just planning on running a single inlet/outlet prop valve for the rear brakes and letting the fronts have full pressure with using a tee. Unless there's a reason not to? 

 

I had found guys in previous threads using the first valve I linked to. I wasn't sure if there was a purpose to using the 1/8 npt fittings instead of the 3/8×24. I'm going to run that line right back to the hose for the rear brakes which  I understand is also 3/8×24. 

Well the model you are referencing isn’t a proportioning valve. It’s a fixed pressure valve. So if your trying to have the back brakes receive let’s say 25% less pressure, at 1000 psi then you can set it to 750 psi but it will be set to a static 750 psi. Meaning your brakes will be a 50/50 pressure split up to 750 psi and then the back ones will be capped at 75 while the line press increases. That husband n example but in real world application it means your back brakes will still be much more likely to lock up under light braking with an unloaded bed. Hope that makes sense

[ghetdjc320]

Never mind, I just referenced Wilwood’s specs and they say it is a dynamic pressure reducer so yes it should work as a prop valve. The 3/8-24 is the one that I’d want. I’m guessing the 1/8npt could work for other applications or perhaps an hose fittings.

[ctxj93]

31 minutes ago, ghetdjc320 said:

Never mind, I just referenced Wilwood’s specs and they say it is a dynamic pressure reducer so yes it should work as a prop valve. The 3/8-24 is the one that I’d want. I’m guessing the 1/8npt could work for other applications or perhaps an hose fittings.

Gotcha. Thank you for the info, much appreciated! 

[Jeep Driver]

If listed as NPT, NPT will allow for adaptors for multiple applications. 

 

If you are running large tires with a KJ or other conversion, you do not need an adjustable prop valve, regardless of what anyone has posted about it. KJ/other discs will not over-brake a large size tire. 

 

Do not discard the distribution block, plug the discarded line and retain the block. 

 

I'm installing Wilwood front and rear. Bled my rears last night and I have good pedal. 

I'll be installing the fronts in a week or so. 

I do not expect to use a prop valve even with 4-pot rears.

I'll post the results in my thread. 

 

If you want to do something which will give you an immediate benefit- new hard lines and braided SS soft lines...along with the later model master/booster. 

 

 

[ghetdjc320]

46 minutes ago, Jeep Driver said:

If listed as NPT, NPT will allow for adaptors for multiple applications. 

 

If you are running large tires with a KJ or other conversion, you do not need an adjustable prop valve, regardless of what anyone has posted about it. KJ/other discs will not over-brake a large size tire. 

 

Do not discard the distribution block, plug the discarded line and retain the block. 

 

I'm installing Wilwood front and rear. Bled my rears last night and I have good pedal. 

I'll be installing the fronts in a week or so. 

I do not expect to use a prop valve even with 4-pot rears.

I'll post the results in my thread. 

 

If you want to do something which will give you an immediate benefit- new hard lines and braided SS soft lines...along with the later model master/booster. 

 

 

I’d scrap the stock block. The machines ports are well under 3/16 line size and aren’t machines well. 
As for locking up tires, with my Wilwood prop valve all the way open for the rear I can lock my 33’s well before my fronts without any load in the bed. I’m running ZJ disks

[Eagle]

1 minute ago, ghetdjc320 said:

As for locking up tires, with my Wilwood prop valve all the way open for the rear I can lock my 33’s well before my fronts without any load in the bed. I’m running ZJ disks

 

Which, of course, is exactly what you DON'T want to have happen. They use proportioning valves on rear brakes to try to ensure that the rears DON'T lock up first.

[Jeep Driver]

3 minutes ago, ghetdjc320 said:

machines ports are well under 3/16

Pressure, not volume. 

 

and.......hang a 200lbs bumper on the back, better ride, better brakes. 

[ghetdjc320]

4 hours ago, Jeep Driver said:

Pressure, not volume. 

 

and.......hang a 200lbs bumper on the back, better ride, better brakes. 

I’ve got a JCR bumper on the back. Unless you’ve got a whole lot more weight back there, the only bias you have is the difference in piston sizes and brake pad/rotor swept area between front and rear. Eliminating the prop valve is not a good idea on a truck with functioning brakes in back. 
 

 

The small ports on the dist block are poorly machined (they are on most oem dist blocks). Regarding pressure, larger diameter distributes that pressure better. In addition, moving to a larger MC bore to compensate for larger caliper piston surface area will move more volume of fluid. It will take longer to push that increased volume through the stock dist block. Granted, this would only apply to brake upgrades involving a larger MC. But yes ultimately the pressure will be the same. Pedal response may be a bit sluggish though. 
 

 

[ghetdjc320]

4 hours ago, Eagle said:

 

Which, of course, is exactly what you DON'T want to have happen. They use proportioning valves on rear brakes to try to ensure that the rears DON'T lock up first.

Exactly, which is why I don’t open my valve all the way up. I will open it up just a bit more with a load in the back. But u adjusted it and tested it thoroughly on loose road conditions to get the best input for where the valve needed to be to provide the right bias.  
 

If we remove any brake bias as @Jeep Driver suggests the backs WILL lock before the front especially on wet roads, ice, gravel and any other loose surface or with no load. The ZJ prop valve is pretty close to a zero bias but the vehicle weight dynamics are far different and as was mentioned, there is already some bias built into the brakes themselves based on piston sizes and pad to rotor contact surface area. 

[ctxj93]

Currently I have an 8.25 out back with brand new drum brakes. It'll be a long time before I convert to discs.  I already have the JCR bumper counterweight back there too. Just want to keep things simple and safe. I'm very used to driving XJs and MJs with tires that are entirely too large, and brakes that are entirely too weak. 

[cruiser54]

This is why you discard the distro block.

Done it both ways. Keeping the distro block and eliminating it. 

Way better overall braking without it. 

See the XJ valve has .100" passages. The MJ distro has .050" passages. 

 

 

[cruiser54]

[Jeep Driver]

On 3/1/2021 at 2:50 AM, ghetdjc320 said:

If we remove any brake bias as @Jeep Driver suggests

Here's what I actually suggested-

 

If you are eliminating the stock prop valve you are already going to replace the soft line there.

The only other thing to do is to plug the distribution block. 

What I suggest is spending $1.99 for a plug, then see what you have. 

 

Every time this subject comes up, here or elsewhere, the immediate question is what adjustable valve do I buy?

 

There is an assumption that the stock valve actually worked, once worked, ever worked, or was needed in the first place or was even necessary. 

Guys are making new linkages, adjusting, readjusting the stock valve under the assumption that it is working or that it is necessary and needed. 

What I will now further suggest is that the stock valve is and was, from the beginning, a gimmick. Maybe it worked 30 years ago, for a while, who knows? but after being articulated for 200K+ miles......eh......

 

For those with drum brakes, I guarantee you, 99 of 100 reading this have not, unless incredibly anal, cleaned and adjusted their rear brakes. The only time rear drums get any attention is when the wheel cylinder leaks. I'll bet you most are operating at 20% if at all. Dirty, rusty, glazed, worn, out of adjustment, leaking.

 

KJ or ZJ or other, they are the same, compare, no different. 

Also, compare front to rear, rears are about 40% smaller, rotor size, pad size, caliper piston size, front to rear- you are already about 40% under-braking at the rear. 

 

Another misconception, bore size- 

First thing I read when doing my research several years ago is big brakes must have a big-bore master. 

For those who spend the big bucks, one could end up feeding 24 pistons.

Larger rotors, rotors are nothing more than levers, larger levers require less work. 

Larger pads, more surface area, more surface area requires less work. 

If more work is being done with less effort, less heat is generated, less heat equates more efficient braking, again requiring less effort. 

More pistons applying pressure over a larger surface requires less energy/effort/work/heat/demand/pressure over a single piston for the same work requirement. 

A 7/8 bore will produce more pressure than a 1 1/8 bore.

 

I'm suggesting that the most immediate benefit one could gain will be braided SS lines. Pressure and volume loss is taking place at the rubber soft lines. 

 

I turned my truck around last night to get ready to do the fronts, immediate lock up of the rears.....they are not scrubbed in yet, obviously. 

I'm now anxious to see how they feel with the fronts done. 

I may have to add a valve, if so I may just go with the Wilwood master with valve.....I'll have to see. 

But, apple to oranges thus far......one thing is for certain though, stock to Wilwood is no comparison. 

 

 

[ghetdjc320]

3 hours ago, Jeep Driver said:

Another misconception, bore size- 

First thing I read when doing my research several years ago is big brakes must have a big-bore master. 

For those who spend the big bucks, one could end up feeding 24 pistons.

Larger rotors, rotors are nothing more than levers, larger levers require less work. 

Larger pads, more surface area, more surface area requires less work. 

If more work is being done with less effort, less heat is generated, less heat equates more efficient braking, again requiring less effort. 

More pistons applying pressure over a larger surface requires less energy/effort/work/heat/demand/pressure over a single piston for the same work requirement. 

A 7/8 bore will produce more pressure than a 1 1/8 bore.

This is true. 90% of the time a larger MC is not needed especially for stock brakes. The ratio from MC bore to Caliper piston size is the basis for hydraulic leverage. However, there is a volume equation in all of this that seems like it’s being forgotten. Not to mention, the booster capabilities. If you run a hydroboost setup there is just no reason to run under a 1” bore with stock brakes. The booster is far more effective at providing assistance so why not up the volume for improved pedal response. This applies equally to vacuum booster setups while running significantly larger caliper sizes. In essence, everything needs to be balanced. 
 

The built in brake bias due to caliper sizes is based on a vehicle with a specific weight distribution. Our trucks for the most parts just don’t fit the bill unless they have a fair amount of cargo weight to equal it out. 
 

[cruiser54]

Dual diaphragm booster with whatever master is on it. I prefer 99 to 2004 WJ.

Ditch the distro valve. Put a union between the front brake lines. Use one line to the rear discs you're using, install a Wilwood prop valve, and eliminate all that monkey motion crap from the factory at the rear.

 

And YES, braided lines make a noticeable difference. I have them on every car I own. Even the clutch slave lines..... 

[ghetdjc320]

3 hours ago, cruiser54 said:

Dual diaphragm booster with whatever master is on it. I prefer 99 to 2004 WJ.

Ditch the distro valve. Put a union between the front brake lines. Use one line to the rear discs you're using, install a Wilwood prop valve, and eliminate all that monkey motion crap from the factory at the rear.

 

And YES, braided lines make a noticeable difference. I have them on every car I own. Even the clutch slave lines..... 

or a hydroboost!