HPP JBV brake pedal is "sticking" a bit; is this normal?

[cameron_etc]

I got my HPP JBV pedal set in the mail the other day and the pedals are excellent. Night and day difference over my T3PAs (as they should be for $1400 lol) and build quality is top notch. However, I've noticed that the brake pedal has a sort of "stickiness" to it. That is, when I initially get on the brake, there's a certain amount of force required to get it moving (almost like I'm needing to overcome some amount of static friction within the hydraulic system), and when coming slowly off the brake, it sometimes "catches" a bit or feels notchy in a sense (so there's not necessarily a smooth progression off the brake pedal). This latter issue tends to more or less disappear after about 30 minutes of continuous use.

I've noticed that application of WD40 onto the exposed part of each piston (that connected to the pedals itself and the one that pushes on the rubber bumpers) can help (WD40 also made the clutch a lot smoother FWIW), leading me to believe that this may be an issue with lubrication.

Is this something that other HPP owners (or even owners of other hydraulic pedal sets, whether closed or open loop) have experienced? For now I'm chalking it up to the pedals being new and still needing breaking in, but this is my first foray into really high-end sim equipment (as I said, I upgraded from my T3PAs and I'm still using my TX base for the foreseeable future) and I'd really like to make sure that this isn't a problem per se (or at least, that it's a problem that goes away after a month of breaking in).

Thanks for any insight

 

[ThomasTML]

Yes, that normal. You can apply some silicon grease and it will stop the sticking for a while. (WD40 last only a few days!)

 

[cackster]

Op did this problem ever go away? Thanks for info.

 

[cameron_etc]

Op did this problem ever go away? Thanks for info.

PMed

 

[mig007]

OP, I'm curious about this as well. I will be trying actual grease soon as opposed to just a spray based lube. I'm using the HPP PRX model.

 

[cameron_etc]

Sure thing. The TL;DR is that it does still "catch" a bit when initially applying pressure but under trail braking it feels very smooth, no catching or anything. I applied some WD-40 to the exposed parts of the master and slave pistons and put some Vaseline on the rubber bumpers. If I had to guess, I think that the initial catching when applying pressure is coming from static friction within the master cylinder, and tbh I don't really want to dive into the mechanism due to its closed loop nature (largely a blessing, but in this case possibly a curse haha). Honestly when actually driving it feels natural underfoot, it's only when I sit in the rig with the VR headset off and paying close attention to the sensations underfoot that I begin to actively notice the initial catch.

I might do some playing around with stiffer bumpers to see if the increase in required force makes a difference (I'm currently running the softest setup), and I'm also interested to see how the closed-loop system responds if I were to replace the bumpers with some not-so-stiff springs just to get the mechanism moving faster. I work at an auto shop so I might grab a couple drops of fresh 0W20 and put it on the exposed parts of the pistons to see if that does anything. On the JBVs at least (not sure about the PRXs), there's a small hole at the back of the slave cylinder, seemingly for air to pass in and out through, so one might be able to better lubricate the slave cylinder walls if you can get a tiny enough syringe tip or something in there.

Sort of on topic but the clutch pedal also required a pretty significant amount of Vaseline to get going smoothly, though now that it's smooth, it's brilliant.

Hope this helps. I'll update this thread if/when I go ahead with 0W20 or some other experimentation.

Otherwise, for anybody reading this who might be wondering, these pedals are fantastic. Gorgeous finish, very compact design, can be inverted but still true hydraulic, throttle and clutch springs are dead easy to swap as are the brake bumpers, the throttle is super smooth, the clutch feels super realistic compared to IRL track cars I've driven despite the simple looking mechanism, and the quality is top notch with proper construction (e.g. not using bolts as pivots but instead using proper clevis pins). Not cheap but alas.

 

[mig007]

Thanks for the quick response Cameron - much appreciated!

I will play around with some grease and see how it performs. Also need to replace my throttle and clutch springs as after nearly 10 years, they're toast (understandably) and might order the bumpers off of the site that should work with this model to see how it feels.

BTW, I do use the stiffer bumper and it helped with the catching by a bit.

Mig