Help with big bore shock caps

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, and others.
M

measy116

Active Member
Messages
57
I was running my xl at the track when I took a giant jump I landed and one of the caps on one of my big bores snapped. For a quick fix I ca'd the retainer that came with the big bores to the broken shock cap so I could run a few more laps around the track. My question is, does anyone kno where I can pick up a set of aluminum big bore shock caps so this doesn't happen again? Or even the stock caps which I can't seem to find anywhere except with a new set of shocks. Thanks for the help!!!
 
hellfire caps ...

Right front...
DSC_0006-2.jpg
 
Question for Bankrupter. How do you get those Hellfire shock caps to seal air tight? I cant get them to seal air tight, they leak out at the little holes. I looked at the Hpi site and the Hellfire shock bladders look the same as the big bores.
 
lol you didnt put the bladder in ? Yes it needs it. Hellfire shock is the same as the big bore. the pic I posted has HF shafts, caps, springs.
 
OK, are the HPI Big Bore bladders the same as the Hellfire bladders? One of my Big Bore Shock caps striped off after 3 hours of use. I took the bladder out of the bad Big Bore cap and put it in the new Hellfire cap. It (HF cap) would not seal air tight.

P.S. Thanks for the helpful thread above. I used the search tab on this subject a half dozen times or more and never found that thread.
 
Last edited by a moderator:
Update.... I still cant get the big bore shock to seal air tight with the Hellfire shock cap. I used the bladder from the big bore shock. They still leak shock fluid out of the two little holes in the HF caps. I even tried a stock big bore shock caps with bladder and it sealed air tight. Any help?
 
Which way are you putting the bladder in? Curvy side up or down? You may need to get new bladders which are not expensive, they are like 3 bucks
 
Ltrus.....how did you make out? I also bought these caps, bladders are good and they don't seal, leak out same as yours. Only thing I can think of is the threads on the aluminum caps, towards the end of the thread closest to the bladder seal. Gonna give the ol' plumbers tape a try.
 
I have been told aftermarket hellfire caps don't work. I don't see how not but it has been said. I know my HPI HF caps are leak free no issues.
 
Sorry, I should have replied earlier. I bought the new bladders and they still leak. I would say not to buy the Hellfire caps for the people that need new shock caps. they don't work!! Not sure how the other members got there's to work for them?

I hate to say it but I put the Savage X on the back burner. Its a money pit, it always has something breaking on it. Went back to my LOSI's.
 
well this is what I found, the threads seamed to be keeping the bladder from seating on the bottom, I used the dremmel to take away some of the thread which was bured any way so I had an even line from the thread all the way around, then I sealed up the bleader holes with some med ca glue. let it sit till hard then carefully install the bladders, keep a close eye and make sure its all the way down and centre. I have no leaks now.
 
Arent the holes in the caps there to allow the pressure to release from between the bladder and cap when the bladder is pushed in? Isnt it like a diaphragm that soaks up the compression and helps to stop the caps blowing off?
 
LTrUS said:
Sorry, I should have replied earlier. I bought the new bladders and they still leak. I would say not to buy the Hellfire caps for the people that need new shock caps. they don't work!! Not sure how the other members got there's to work for them?

I hate to say it but I put the Savage X on the back burner. Its a money pit, it always has something breaking on it. Went back to my LOSI's.
Click to expand...

and your losis don't break? comon any rc you drive is gonna break or your not driving it
 
Yes my Losi's and TeamAE do bake. It just seems that my Savage brakes every other time I take it out. Its a fun truck to run around for sure. Its just not as tough as I was led to believe. I will try to seal the holes in the caps and see if that works along with fixing the engine mount plate, I noticed it was cracked the last time I toke it apart.
 
I'm having the same problem with these caps leaking. Not buying into sealing the holes since they are on the threaded portion below the bladder where the seal is made. The flange of the bladder should create a gasket seal between the body and the cap.

I'm wondering if there is a height difference in the threaded area of the cap that is creating either over or under tightening of the flange/bladder.

Anyone?
 
Leaky caps

Since I'm having the same problem with leaking caps as many others out there I thought Id look into it further. Brought some calipers home from work and took some measurements. Heres what I found.

The depth of the caps ARE DIFFERENT! The Hellfire aluminum caps are .034" shallower than the stock plastic BB caps. This doesnt seem like much but what I think is happening is that the bladders are being over tightened which is squeezing the flange of the bladder into the shock creating the leak.

These are the measurements I recorded.

Stock cap depth .276" 7.0104 mm
86542 alum cap depth .242" 6.1468mm

Difference .034" .8636mm

Length of threads on BB body .215" 5.461mm

Seems the solution would be to use shims so as to not overtighten the bladders. The diameter of the threaded portion measures .667" 17mm.

If anyone has any info on a part number for shims that might work 17mm id, It would probably help a lot of people.
 
You must log in or register to reply here.

Latest posts

Members online

Total: 210 (members: 1, guests: 209)
Back
Top