should read engage hubs.

 

I think it's a seal behind the wheel bearing?

 

There are two seals that can leak. There is the seal behind the wheel bearings like most rigs have, and there is another seal on the back of the spindle where the CV axle butts up to it. The likely bad one would be the axle shaft seal. There was a TSB indicating a redesigned axle/spindle/seal setup due to common vacuum leaks. The problem is that if it was not updated in the past, you have to change the spindle and half shaft if you want the new design.

I tried finding replacement seals for the old design at the parts houses here in town but they could only provide the newer redesigned ones that will not work on the old setup. Honestly though I did not look that hard.

It's not hard to replace the seal. Just remove the tire, locking hub, axle retainer ring, pop the upper ball joint loose, and pull the axle through. There is just enough play in everything to wiggle the axle out of the way and replace the seal.

 

You can find that TSB, technical service bulletin, in kiatechinfo.com, its title is "Sportage Front Hub Seal Change" and the TSB number is 007 revised, of March 2001. It says that the new seal design was introduced since 10/21/00 production, while the 4WD Sportages produced between 9/1/97 and 10/21/00 have the previous seal design. So my Sportage has got the previous seal design, but its vacuum hubs work, I just checked their airtight today with my hand vacuum pump.

That TSB says that there is a kit available to retrofit the new seal design to the Sportages with the previous seal design, and gives all the instructions to accomplish that work. But I think that that kit includes new half shafts, so I think that it is very expensive.

I also think that there is no problem to obtain the right seal going to a KIA spare parts warehouse with your Sportage VIN number.

 

Anyone catch that? "mechanic stated there was only 10 lbs". Where did he measure 10 lbs? was that 10lbs created by the engine or with his hand pump tool? with his hand pump tool he should have been able to tell you which location the leak was at.. either the vac leak is in one/both of the hubs OR in the vacuum lines or 4wd vacuum solenoid. If all he did was hand pump vacuum with his own vacuum line connected directly to the hub and he only could reach 10lbs, then the hubs aren't holding vacuum enough to engage. But if he attached his hand pump/gauge to the line that would go directly into the hub and the engine running could only pull a 10lb vacuum to his gauge, that tells the mechanic there's a vacuum SUPPLY issue.. IE: dry rotted or torn vac lines, or a clogged 4wd vac solenoid. We need to divide and conquer the system here. There's the hubs and the lines. we don't want to put in new hub seals if the problem is the vacuum lines.. nor to we want to pull our hairs out NOT finding vacuum leaks in the system if it's been the hubs all along. This is a diagnostic I've had to do with my own sportage and also a few Ford Superduties as they have a simliar vacuum system, theirs is more complex however. Ours just needs ample vacuum to overcome spring tension. Ford's uses two separate vacuum rates. One is to engage the hubs, and the other to disengage.. there's no vacuum used while staying in 2wd or 4wd on them.. it's only during the transfer.. and the hub resembles the same principle as a pen.. ya.. you know.. 'click' (in) 'click' (out).. click click click click, lol.

 

My Sportage front left half shaft

Although the TSB says my Sportage should have the previous style half shaft, the one on my Sportage seems to me to be of the new style; and my Sportage was produced in mid 1999.

 

First I'd look into why "PRESSURE" is considered when it's a "VACUUM" system. OK, maybe you are meaning "negative" pressure. Do both hubs hold "negative" pressure or vaccum when tested individually ? Yes ? Then it's in the hoses/tubing/solenoid/vacuum("negative" pressure) tank or poor running eninge that does not produce a stong enough vacuum. No ? Then there is a bad seal, bearing or sealing surface on the knuckle or outer CV joint.