Master Cylinder replacement issue - Hyundai Genesis Forum
 
LinkBack Thread Tools
post #1 of 4 Old 02-03-2019 Thread Starter
Member
 
RicanGen20T's Avatar
 
Join Date: Mar 2011
Posts: 89
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
(Thread Starter)
Master Cylinder replacement issue

My 2010 Gen Coupe was having brake issues and I took it to Pep Boys for a diagnostic. They determined that it was the master cylinder.

I ordered the same one from Rock Auto, we replaced it and did all the bleeding before and after installing the Master Cylinder and everything felt fine.

However, if I start the car without putting my foot on the brake pedal initially, when I press the brake pedal to put car in gear (AT) and every time the pedal is pressed, I hear like an electric pump, just like the one you hear when you first start the car; which I'm assuming it is the gas pump, but this sound comes one every time I press the brake pedal and sometimes when I release it.

Now, if I start the car with my foot on the break, then that electric pump will not come on.

Brake fluid is fresh, brake pads are still good and there are not leaks anywhere that I can tell.

I am suspecting that air is still in the lines or abs system and that the pump is coming on when I press the brake pedal to compensate pressure that is lost from the space air in producing in the system.

I'm not a mechanic, I don't know if this is even possible. What causes that whatever electric pump to come on only when I press or release the brake pedal and only when I start the car without pressing the brake???

I was told that the abs had to be bled also but with the scanner; which I took to a shop and they claim they did.


What am I missing?

2010 GC 5sp AT
Present Status:
- HKS Catback Dual Dual Exhaust
- Test pipe
- AEM Cold Air Intake
- Mishimoto Intercooler
- Rebadged
- M&S Grill
- HID Projectors
- Racing Lubricants
- SFR Reflash 1.5
- Tinted windows
- That little special something...
What comes next to reach status of
- Rims
- Wing Spoiler
- Rear deffuser
- Not sure what else...
RicanGen20T is offline  
Sponsored Links
Advertisement
 
post #2 of 4 Old 02-04-2019
I'd rather do it myself
 
Red Raspberry's Avatar
 
Join Date: Aug 2009
Location: Flat lands of Illinois
Posts: 18,235
Mentioned: 21 Post(s)
Tagged: 1 Thread(s)
Quoted: 3 Post(s)
Garage

The auto trans models have a vacuum pump that should come on when the vacuum switch closes. The switch is located on the pass side of the master cylinder and power for it is from the ESC module. I would guess either the switch is bad or you are loosing vacuum on the brake booster or this is just normal operation and you have not noticed it before?

Logic is from the ESC module that grounds the pump relay coil through a driver on the module when the switch is closed.


2010 Red 2.0L track

Quote:
If the Pharaohs had duct tape, the Sphinx would still have a nose...."
Red Raspberry is offline  
post #3 of 4 Old 02-27-2019 Thread Starter
Member
 
RicanGen20T's Avatar
 
Join Date: Mar 2011
Posts: 89
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
(Thread Starter)

The booster does have a sensor, you are very right. But I can't find anywhere what type of sensor that it so that I can replace it. Nor can I find that same exact booster anywhere online.

I'm sure that this behavior is abnormal. I've had this car from day 1 and cero miles, so I know it's good and bad habits.

Specially the startup buzzing when I turn the key in the ignition. I don't know if it's the gas pump loading or the abs/brakes loading, but I do know that now it takes longer to stop.

2010 GC 5sp AT
Present Status:
- HKS Catback Dual Dual Exhaust
- Test pipe
- AEM Cold Air Intake
- Mishimoto Intercooler
- Rebadged
- M&S Grill
- HID Projectors
- Racing Lubricants
- SFR Reflash 1.5
- Tinted windows
- That little special something...
What comes next to reach status of
- Rims
- Wing Spoiler
- Rear deffuser
- Not sure what else...
RicanGen20T is offline  
 
post #4 of 4 Old 02-27-2019
I'd rather do it myself
 
Red Raspberry's Avatar
 
Join Date: Aug 2009
Location: Flat lands of Illinois
Posts: 18,235
Mentioned: 21 Post(s)
Tagged: 1 Thread(s)
Quoted: 3 Post(s)
Garage

Dealer wants around $500 for the booster.

I have some vacuum switches. You could tee off the line feeding the booster and connect the switch. It will come on at around 1" Hg vacuum.

There is also a check valve in the hose going from the intake to the booster, make sure that is working as it should. Should be closed when in boost.

https://www.jimellishyundaiparts.com...=vacuum%20pump

2010 Red 2.0L track

Quote:
If the Pharaohs had duct tape, the Sphinx would still have a nose...."
Red Raspberry is offline  
Sponsored Links
Advertisement
 
Reply

Related Threads
Thread Thread Starter Forum Replies Last Post
MMmmH!...Clutch master stage 3...3 month later..clutch cylinder is death... :S matcoupe Drivetrain 8 07-09-2017 11:35 AM
Slave cylinder replacement question David Tilley Drivetrain 4 05-23-2017 07:35 PM
****Karbon Koncepts**** CP-E 2.0T Factory Intercooler Replacement Kit karbonkoncepts Engine 0 03-09-2015 01:35 PM
Screw bolt-ons, BC 4.2L stroker! The first for the street. J_Tex 3.8 V6 Discussion 2008-2012 160 02-10-2011 03:28 PM
2.0T R-spec tranny/slave cylinder problems Swift52686 Engine 11 12-14-2010 08:14 PM


Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Hyundai Genesis Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome