I X-Ray CT Scanned My Old Clutch Master Cylinder

"FTTOHG Has Moved to https://opposite-lock.com" (alphaass)
04/19/2017 at 17:52 • Filed to: CT SCAN, HYUNDAI SANTA FE

A few years ago when I still had my Santa Fe, I replaced the clutch master cylinder, because pedal felt crunchy. It wasn’t leaking, but the travel wasn’t linear and there was a squeaking sound coming from somewhere near the firewall. I still have the old part, so out of curiosity, I decided to CT scan it to see what was up. Despite being a mixture of different metals and plastic, the scan turned out OK at 200 kV and 200 uA. The steel parts made some artifacts, but I was still able to isolate it pretty well. In the images below, the return-assist spring is on the lower left. It’s pretty much destroyed. The spring doesn’t bring the pedal back up alone - hydraulic pressure does most of that - but it does help keep it centered, which explains the symptoms that I was having. Neat! XCT is a pretty nice tool for finding defects hidden inside of things that you can’t easily open up. At least one automaker scans every cylinder head they cast before it goes into a car. Hopefully I won’t be needing to scan any more parts off of my cars any time soon, though!

These are the steel parts. On the bottom left is the messed up return spring. Up top are retainers for the hydraulic hoses. On the right is the rod that connects the piston the clutch pedal. The fork that hooks into the pedal is a lighter plastic part so it isn’t in this image.

Cut-plane view. Here we can see the piston itself as well as the hose attached two openings on the cylinder and the fork that connects to the pedal that weren’t visible above. I was surprised to see how much porosity there was in the piston molding itself, but it held up better than the spring so it durability is good enough.

DISCUSSION (10)

RallyWrench > FTTOHG Has Moved to https://opposite-lock.com
04/19/2017 at 18:00

That is pretty much the coolest thing ever, I wish I could do that for every failure I see.

If only EssExTee could be so grossly incandescent > FTTOHG Has Moved to https://opposite-lock.com
04/19/2017 at 18:02

I think the thing about this that amazes me the most was that they made a manual Santa Fe.

FTTOHG Has Moved to https://opposite-lock.com > RallyWrench
04/19/2017 at 18:15

I’m very lucky to have access to a machine. They are becoming more and more common, but they still cost over $500k and require a lot of maintenance and training to keep going. So rates are expensive. I’m down the road in SA, so if there ever is something you need to see inside of give me a shout and I’ll see what we can do.

FTTOHG Has Moved to https://opposite-lock.com > If only EssExTee could be so grossly incandescent
04/19/2017 at 18:19

Even more amazing - they made one all they way until 2012. Mine was a 2007, first year of the 2nd generation, with a 2.7L V6 and 5MT. For 2010, they switched to a more modern 2.4L I-4 that was only down something like 10 hp and paired with a 6MT to keep acceleration basically the same and get a few more MPG. In both cases it was FWD only. Believe it or not, the clutch and shifter were actually pretty decent, and the thing gave you a pretty good tug of torque steer, because 1st was a very low ratio.

Blind Willie Tyresmoke Namington IV > FTTOHG Has Moved to https://opposite-lock.com
04/19/2017 at 18:29

That is so cool. I think that with access to a tool like that I would end up being fired for scanning absolutely everything I can get my hands on for no purpose other than my own entertainment

RiceRocketeer Extraordinaire > FTTOHG Has Moved to https://opposite-lock.com
04/19/2017 at 18:32

That is fascinating stuff.

FTTOHG Has Moved to https://opposite-lock.com > Blind Willie Tyresmoke Namington IV
04/19/2017 at 18:39

We’ve had some fun. One of my favorites was seeing all of the seeds inside a pumpkin. But fortunately it’s been so busy with real work recently we haven’t had much chance to goof around.

Frank Grimes > FTTOHG Has Moved to https://opposite-lock.com
04/21/2017 at 01:25

Where can I get one for my garage?

FTTOHG Has Moved to https://opposite-lock.com > Frank Grimes
04/21/2017 at 07:26

Lol. You need to have a little chat with the FDA first.

Frank Grimes > FTTOHG Has Moved to https://opposite-lock.com
04/21/2017 at 14:02

I am sick of dealing with those bastards.