Hyundai Forums banner

1 - 3 of 3 Posts

·
Registered
Joined
·
2 Posts
Discussion Starter #1
Hello,

New user here. I have read the forum but haven't found any related posts. I have my XG300 2001 for quite a while, it has been actually in the family since new. I am aware of all the terrible issues that this car had and still has, as we have went through a lot of them. At this point though, the car is like a live person with a mind of its own. It shows CEL sometimes, then it goes away. It does have occasional weird problems as trying to stall or RPM changes, but it doesn't bother me, as I will ride this workhorse until something serious happens.

Issue is as follows:
I have changed all rotors and brake pads some time last year or even year before that. The rotors came from Ebay, crossdrilled, pads from same source. After all was put in, I immediatelly noticed that braking didnt improve at all, but actually was even worse. Now I kind of let that issue slide, since knowing that if you get too involved with this car, it might cost quite a bit of nerves. Recently in the last 6 mo or so, I am annoyed at the braking problem, as it's gotten a little worse and want to finally deal with it.

The basic feel is that the power assist doesn't act in full force. Comparing to my Audi A4 08, I have to apply 2-3 times more physical pressure on the pedal to get the same braking, and to hold the car in place at a stop. I did get used to it over a period of time, but it is annoying when switching cars, and it just feels wrong.
My mechanic is an honest guy, and after testdrive said, that the brakes do feel harder than they should and he could sell me anything from master cylinder to brake lines, but I should start with changing pads to OEM and see what happens.
My logic is, that pads affect braking, but do not affect the pedal feel, as I should be able to hold the car in place at a stop with ease, no matter if the pads are worn, bad or good. What happens though is that all the soft range of the pedal movement it barely applies any braking and only starts grabbing when I approach the bigger pedal resistance, and to brake hard I would have to really step on it, I'd say it feels somewhere at 1/3 the effort of applying brakes while the engine is off. It's a consistent feel, without any sudden changes in pressure, no pedal sagging(to my relative observation). It seems that it could be related to brake booster or master cylinder, but open to hear suggestions. Is there a way to adjust the pedal itself, so that the grabbing range moves into the initial pedal travel when it feels smooth?

I saw another person with XG300 ask this question somewhere from my last Google search, but cant find it now. This seems to be not a common occurrence.
Forgive the long post. WOuld also take suggestions on brake pads...is OEM really the only way to go? Since my rotors arent OEM, I suppose they can handle the extra heat. I want good braking, like the car had when new, not this underpowered performance.

Much thanks.
 

·
Registered
Joined
·
17,552 Posts
Go out to car, hop in front seat.. DO NOT START CAR --- press pedal a couple times till it is hard.

With moderate pressure on the pedal, start engine... the pedal should sink a bit as vacuum hits the boost cylinder..

Likely your change in pedal feel has to do with the friction co-efficient of different material pads and rotors..
 

·
Registered
Joined
·
2 Posts
Discussion Starter #3
QUOTE (sbr711 @ Jun 9 2010, 12:29 PM) index.php?act=findpost&pid=331277
Go out to car, hop in front seat.. DO NOT START CAR --- press pedal a couple times till it is hard.

With moderate pressure on the pedal, start engine... the pedal should sink a bit as vacuum hits the boost cylinder..

Likely your change in pedal feel has to do with the friction co-efficient of different material pads and rotors..
Have done a check for that before. Seems fine. Pumping the pedal till its hard, moderate pressure, start, it sinks quite a bit.

Can a brake booster, master cylinder be malfunctioning for years without deteriorating and breaking down completely? Or they are usually a part that fails completely when it does. I am guessing I should check the vacuum hoses, valve at the booster, but not a mechanic, don't know the proper procedure.

Thanks for the info.
 
1 - 3 of 3 Posts
Top