Wilwood radial mount calipers

[Bill Johnson 42]

Anyone using the new Wilwood radial mount calipers?

Last year used the lug mount Wilwoods on original cast uprights on my 01 Van Dieman FC. The calipers worked very well but wanted to upgrade my uprights so I went with the radial mount Fast Forward uprights and these Wilwood radial mount calipers. Have only used them one weekend but I'm incredibly unhappy with them. Can't get a hard pedal like I'm used to and I've taken these things off the uprights and bled them upside down and right side up. Just went to the expense and time and replaced all of the master cylinders just to make sure they weren't the problem.

Also these calipers don't seem to release the rotor as freely as my old calipers.

If anyone is using these would like to hear your results.

[SteveG]

Bill,

I talked to Wilwood before buying the LD20 replacement and their tech person was extremely helpful on pre-sales questions. I would expect that they are just as good after sales.
Call them and ask.
I would suggest patience though, it took me a week to get the call back.

Steve

[t walgamuth]

I don't know what is meant by radial mount, but my new aluminum calipers by willwood have been a devil to bleed. I have not succeeded yet. Two events with very dodgy brakes so far.

[DaveW]

I don't know what is meant by radial mount, but my new aluminum calipers by willwood have been a devil to bleed. I have not succeeded yet. Two events with very dodgy brakes so far.

I used to have some calipers that needed to be tilted so that the internal bleeder passages were at the very top to bleed successfully.

Radial mount means the attaching bolts are perpendicular to the axle. Lug mount bolts are parallel to the axle.

[BrianT1]

Hi Bill,

I have no experience with the Willwood Radial Mount calipers but I do run the PFC Radial Mount calipers and I know when I rebuild them and change all the seals the calipers take about a session to set everything and then after a final bleed at the track they give a hard and firm pedal.

If yours are not doing that after you have run them then it seems there is air in there somewhere. So if you have bleed them at all angles and still can't get the air our you might consider switching to the PFC. The only thing about the PFC calipers that I don't like is that the pad cost is extremely high. Other than that they are a good caliper.

Brian

[DaveW]

Hi Bill,

I have no experience with the Willwood Radial Mount calipers but I do run the PFC Radial Mount calipers and I know when I rebuild them and change all the seals the calipers take about a session to set everything and then after a final bleed at the track they give a hard and firm pedal.

If yours are not doing that after you have run them then it seems there is air in there somewhere. So if you have bleed them at all angles and still can't get the air our you might consider switching to the PFC. The only thing about the PFC calipers that I don't like is that the pad cost is extremely high. Other than that they are a good caliper.

Brian

Something of note here: IIRC, the PFC's are larger, so some wheels may not clear them.

[Bob Wright]

My information is the PFC radial caliper is no longer made and parts are almost impossible to find. The bleeding and pedal feel of the Wilwood is something that needs to be figured out AFAIK, that's the only available replacement.

[J Leonard]

What part numbers or name of series Wilwood did you convert from to. Seems some Wilwoods flex and never have a hard pedal.

[Bill Johnson 42]

Hey Brian - I thought these would change after the first session or 2 but they did not. For an old school right foot braker, consistent pedal position is kind of important, otherwise it puts your foot in the wrong position relative to the throttle. Also had to brake about 100' earlier than others in a couple places. Not sure if it's related, hope it is, but the pads don't seem to release from the rotors very well. More drag than there should be with no pedal pressure.

I think tonight I'll make a pedestal to hold the brake caliper so I can remove it from the upright and move it around while I bleed it and see if that helps like Dave suggested.

Thought I was joking when I told you I had spent a lot money to upgrade my car but would probably end up going slower - turns out that's what happened.

[BrianT1]

Hey Brian - I thought these would change after the first session or 2 but they did not. For an old school right foot braker, consistent pedal position is kind of important, otherwise it puts your foot in the wrong position relative to the throttle. Also had to brake about 100' earlier than others in a couple places. Not sure if it's related, hope it is, but the pads don't seem to release from the rotors very well. More drag than there should be with no pedal pressure.

I think tonight I'll make a pedestal to hold the brake caliper so I can remove it from the upright and move it around while I bleed it and see if that helps like Dave suggested.

Thought I was joking when I told you I had spent a lot money to upgrade my car but would probably end up going slower - turns out that's what happened.

Yeah that spending on certain things sometimes has the opposite effect than what you want. To be honest I was considering going to the Wilwood calipers because the pad choice is greater and cheaper than what you get with the PFC. right now I’m glad I didn’t but I hope you get them working ok. Let me know what happens.

Brian

[problemchild]

On Feb 18, Andy Hill advertised some rebuilt PFC calipers on the FC facebook page.
If someone needs some ..... maybe still available.

If someone really needs a more traditional solution, I have old-school iron lug-mount LD-20 calipers for sale. With the pandemic situation, I don't think the new alloy calipers (from different manufacturers) are yet available again from the UK.

[DaveW]

...Not sure if it's related, hope it is, but the pads don't seem to release from the rotors very well. More drag than there should be with no pedal pressure.

I think tonight I'll make a pedestal to hold the brake caliper so I can remove it from the upright and move it around while I bleed it and see if that helps like Dave suggested...

Not releasing properly is, IMO, another possible sign of a lot of air remaining in the system. It acts like a spring holding the pads against the rotors.

A bit of drag, however, may also be a sign that the seals are not moving as freely as they should (acting like springs similar to what I said about air in the system), and if that is the case a bit more use "should" loosen them up.

If that's the case, forcing the pistons in and then back out should help by lubing the seals with fluid.

[Phil Creighton]

Years (many) ago I went on a street Girling brake course in the UK and they mentioned that sometimes it was necessary to hold pressure on the pedal overnight to get the seals to "take a set". The even had a special pedal depressor available!!
Its worked for me on race cars on occasion.
Vacuum or pressure bleeding?
Phil

[stonebridge20]

So when I get an MGB in the shop for a fluid service and find that some cheepskate has put on a clutch slave other than OEM spec, I have to reverse bleed the system or I can not get any sort of pedal due to improper bleeder placement on the slave.

Sports bottle with a hose to the open bleeder that you've bleed as much air out of prior to putting it on the bleeder and then push the fluid through the cylinder and back up into the empty master reservoir.

Maybe something to try with these calipers ?

[Bill Johnson 42]

Thanks to everyone for all the suggestions. After using a combination of all of the ideas I finally have a brake pedal back.

I did remove the calipers, turned them upside down, tilted them every direction and used multiple bleeding methods including pressure bleeding.

Since I had new master cylinders I even put a clamp on the brake pedal overnight to compress the master cylinders as Phil suggested and surprisingly, at least to me, that made a difference.

Before I started bleeding the calipers again, I did pull the pistons from the front calipers to make sure there wasn’t any problem with them. These calipers have an anodized aluminum piston with a stainless steel insert heat shield. The heat shield sits on a pin on the piston with a wave washer behind it and a circlip on the front to hold it in place. Since the pistons with the heat shield matched the specs of the stainless pistons of my Wilwood lug mount LD 20 version calipers I swapped pistons and am using the stainless piston out of the lug mount version. All seems good now.

Thanks again

[problemchild]

I hate the pricing of Performance Friction and AP and Alcorn, and the supply of UK product is all messed up with the pandemic, but I hear too many negative stories about the cheaper brands.

[BeerBudgetRacing]

I hate the pricing of Performance Friction and AP and Alcorn, and the supply of UK product is all messed up with the pandemic, but I hear too many negative stories about the cheaper brands.

I see your point but maybe a different/wider perspective is in order...

- Does anyone ask for help when they don't have a problem? How many are installed with Zero problems? We don't know.
- Cheaper is also a perspective. A company and products like Wilwood are quite respected (and not considered cheap) in the mass production car after market. BMWs, Corvettes, Camaros, Mustangs. This is their market. A yearly production of any one of those brands/models is larger than us.
- Which is because we live in a bespoke world. The LD20 market for example is very limited. I for one respect their willingness to even enter this market with their WLD20. If I need to replace the LD20s or LD19s I have I'd be willing to give their product a try.

I'm glad he got them working - but the alum pistons (thermlock) make we wonder if that's worth the extra. Hmm.

Just food for thought.

[problemchild]

I see your point but maybe a different/wider perspective is in order...

A company and products like Wilwood are quite respected (and not considered cheap) in the mass production car after market. BMWs, Corvettes, Camaros, Mustangs. This is their market. A yearly production of any one of those brands/models is larger than us.

Maybe that is the problem. In my totally unscientific anecdotal memory bank, I recall about 10X the Willwood horror stories as the other brands combined. Probably totally unfair, but I know which brand I won't be switching to

[lowside67]

It's funny, over here in Stohr land, the newest Wilwood 2-piece radial design is being raved about as a "must-do" upgrade over some of the older offerings and has had nothing but top comments.

-Mark

[cjsmith]

I installed Willwood LD 19 and 20s on my FF 2 years ago. I haven’t had any problems with them and have very consistent breaking capacity. I learned a good lesson from Greg a couple of years ago. Instead of pumping the pedal a number of times then releasing the pressure at the caliper and only moving a small amount of fluid and air was to install a hose with a vertical loop or arch, to allow the fluid to stay in the hose which works as a check valve before going into the catch bottle. Open the vent line with the clear tube installed and continually pump the peddle. This forces anything in the lines to flow to and through the caliper. The other way could allow air that was trapped in the line to migrate back to a high point between pressurizing cycles. I can bleed all my brakes by myself in under 5 minutes and have confidence I have removed any air. Just make sure you have sufficient fluid in the master cylinder before starting.

[CGOffroad]

I installed Willwood LD 19 and 20s on my FF 2 years ago. I haven’t had any problems with them and have very consistent breaking capacity. I learned a good lesson from Greg a couple of years ago. Instead of pumping the pedal a number of times then releasing the pressure at the caliper and only moving a small amount of fluid and air was to install a hose with a vertical loop or arch, to allow the fluid to stay in the hose which works as a check valve before going into the catch bottle. Open the vent line with the clear tube installed and continually pump the peddle. This forces anything in the lines to flow to and through the caliper. The other way could allow air that was trapped in the line to migrate back to a high point between pressurizing cycles. I can bleed all my brakes by myself in under 5 minutes and have confidence I have removed any air. Just make sure you have sufficient fluid in the master cylinder before starting.

Ditto.... I use the same method described here and have Wilwood WLD20 all the way around the RF97. Zero problem with confidence, or wondering what will happen when I press the center pedal on this car.

Make sure to use a good quality, hi temp racing brake fluid. I learned this lesson years ago. The expense of brake fluid is significantly cheaper than problems associated with using a fluid that is not meant for the job!

[DaveW]

I installed Willwood LD 19 and 20s on my FF 2 years ago. I haven’t had any problems with them and have very consistent breaking capacity. I learned a good lesson from Greg a couple of years ago. Instead of pumping the pedal a number of times then releasing the pressure at the caliper and only moving a small amount of fluid and air was to install a hose with a vertical loop or arch, to allow the fluid to stay in the hose which works as a check valve before going into the catch bottle. Open the vent line with the clear tube installed and continually pump the peddle. This forces anything in the lines to flow to and through the caliper. The other way could allow air that was trapped in the line to migrate back to a high point between pressurizing cycles. I can bleed all my brakes by myself in under 5 minutes and have confidence I have removed any air. Just make sure you have sufficient fluid in the master cylinder before starting.

Ditto.... I use the same method described here and have Wilwood WLD20 all the way around the RF97. Zero problem with confidence, or wondering what will happen when I press the center pedal on this car.

Make sure to use a good quality, hi temp racing brake fluid. I learned this lesson years ago. The expense of brake fluid is significantly cheaper than problems associated with using a fluid that is not meant for the job!

I use the same method to bleed on all of our vehicles. Works perfectly for a 1-person operation. I use Castrol DOT-4 synthetic brake fluid (used to be Castrol LMA), again, for ALL of our vehicles - cars, tow vehicle and racecar. It works great and no worries about water absorption lowering brake fluid temperature capabilities or causing corrosion. It's also relatively inexpensive and lubricates well, extending seal life.

[stonebridge20]

I use the same method to bleed on all of our vehicles. Works perfectly for a 1-person operation. I use Castrol DOT-4 synthetic brake fluid (used to be Castrol LMA), again, for ALL of our vehicles - cars, tow vehicle and racecar. It works great and no worries about water absorption lowering brake fluid temperature capabilities or causing corrosion. It's also relatively inexpensive and lubricates well, extending seal life. [emoji106]

Every vehicle that goes through my shop is done the same way and with the same fluid.

[tstrong]

Every vehicle that goes through my shop is done the same way and with the same fluid.

a third for both the technique and fluid. Has served me well for 30 yrs. Todd