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HPP jBV Help needed

Hi all!
I have owned some Second hand JBV 2P pedals for about 6 weeks.
Knowing that the JBV's are a relatively new release I thought they would be perfect to upgrade from the Logitech pedals I had for 10 years.
Long Story short I have had a few bizarre issues of late.
I contacted Mark at HPP and he said he Can tune them up for me which is shy of impossible with me living in New Zealand and the complications with the Covid pandemic.
1. Throttle inputs were having large spikes. Making very smooth inputs turn into erratic Spikey inputs , Sometimes 15% throttle would jump to 80%. (have given the pedals a good Clean up and removed all dirt to no evail).

2. Slave cylinder O ring split while racing one day and Dumped all its fluid out on my carpet. (Resolved Easily)

3. I 3d modeled and built a Clutch pedal which worked well for some time. Recently now the X axis has started making random button Presses while using the pedal. The button Presses are coming from the HPP board which is effectively impossible seeing as the JBV now use an HPP designed board instead of the LEO bodnar bu0836 like in the PRX's so do not support extra Inputs. I have swapped clutch and Accelerator around between the X and Y axis and it does not fix the Problem with the X axis.

Lastly what SHOULD I be using for brake fluid/ Oil? Of course there are lots of conflicting arguments around this topic.

Thanks to all in advance.


I have PRx pedals, just bleed them using oil, mobile 1 0W30, also bleed them with Dot 4 Brake fluid.
I am of the opinion that they seem to be firmer with brake fluid, but bleed perfectly well with oil.
I doubt very much if anyone could tell the difference.
With brake fluid a leak is very hazardous, oil is a
nuisance at best.
With the circuit board which looks like the most obvious source of the problem from what you have said.
With modern electronics and no array of test equipment, let alone a circuit diagram, the only recourse you have is with a X10 to thoroughly inspect the board for dry joints. :)
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Happily, I've never had to muck about with braking circuits of any kind (real or sim) but yeah, that DOT brake fluid seems to be truly nasty stuff.
A spot of googling implies that one of the key reasons it's used is the high boiling point, which matters a lot in real cars but a little less on sim pedals. I guess anything at all with low enough viscosity and vapour pressure might work?
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one of the key reasons it's used is the high boiling point
FWIW, I am unfamiliar with the subject pedals, but know a fair amount about real automotive seals
specifically designed for compatibility with DOT brake fluids,
which substantially differ from seals designed for motor oil or e.g transmission fluid.
(Some hydraulic power steering seals are incompatible with automatic transmission fluid.)
Elastomer seals compatible with motor oil were traditionally incompatible with DOT brake fluid and vice versa...
These seals are intended to slightly swell, but not soften, with the fluid for which they were formulated.
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HPP advice is to use thin oil, he says 3 in 1 is fine to use, I just randomly decided on 0W30 as that is what I had in the garage.:roflmao:
I can say that it works just fine. You hardly need to worry about the boiling point of the fluid, unless of course your heavy braking is going to create 700 deg C.:D:D:D
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This right here is why i wish i did some more research on my own before purchasing a set of 2nd hand PRX pedals. The support is very lack luster from mark. He says that he doesnt sell rebuild kits for any of his pedal line ups...but you can send the pedals in to have him rebuild them for $250usd.. for real? there isnt even $100 worth of seals and fluid in a rebuild.
2nd of all the pressure sensor failed on mine and he wanted $275usd plus shipping for a new sensor and claimed the sensor was custom built in a factor to his specifications....Yea i sourced the exact same type of sensor with the same specifications with a wiring harness from SimCoaches for $35usd.
I ordered a new seal for the master cylinder piston (which you cant just buy 1, you need to buy a minimum of 100 seals in the pack) for $30usd.
so far i've had no leaks, but if these pedals ever leak again, im re-building them and selling them. i enjoy the feel of the brake pedal and the overall quality is good i think but the service is **** and any replacement parts from HPP seem to come with a 300% mark up
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Thankyou for the honest response, pretty much in line with what I have observed.
I bought my seals from Germany , I suppose that is the advantage of living in Europe for £3, for three of them Including postage.
I wanted 2 rubber bumpers from HPP,, these are interchangable from his latest pedals.
$12 each , I get that bit, but he was charging $60 to post, it is only marginally bigger parcel that is a letter sized parcel.
I just refuse to pay that,for a $24 of small items, even from USA.
This is a useful bit of information about the sensor, again , thank-you for that.
I see no reason why these pedals will not last me for years, I have no intention of letting them go.
I have some HE pro’s as a back up, so that is an advantage. :)
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