 Brakes are killing my leg....major pressure needed to stop the car. |
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| carcus |
 Oct 26 2016, 09:55 PM
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#1
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Member  Group: Members Posts: 223 Joined: 16-March 16 From: Colorado Springs Member No.: 19,760 Region Association: Rocky Mountains  |
Brakes sucked when I got the car, leaking caliper, bad master. Got all new wheel bearings, new rotors, pads, master. No leaks in the system. I have to mash the brake pedal down and it still takes lots of effort to stop. My last 914 was not like this. The mechanic adjusted them but think he forgot to check the pedal adjustment. Any tips to this? Am I missing something. This is about the brake pedal movement to stopping the car. Even at a red light I need to use alot of pressure to keep the car from rolling. The brake pedal should not have that much effort. Really makes the car not fun to drive. And there is really no bite to the calipers to slow it down if I have to slam on the brakes.
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| Dave_Darling |
Oct 26 2016, 10:22 PM
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#2
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914 Idiot Group: Members Posts: 14,981 Joined: 9-January 03 From: Silicon Valley / Kailua-Kona Member No.: 121 Region Association: Northern California 
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Get rid of that Mercedes 23mm master cylinder. Switch back to a 914 17mm one.
Actually, I'm guessing you have a 19mm one? The 17mm one will require about 25% less effort for the same stopping force. Also check that the floor that the master cylinder bolts to isn't flexing--McMark and Racer Chris both make braces to help keep the MC from moving. And check your brake lines when someone stands on the pedal. --DD |
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| Elliot Cannon |
Oct 26 2016, 10:28 PM
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#3
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914 Guru Group: Retired Members Posts: 8,487 Joined: 29-December 06 From: Paso Robles Ca. (Central coast) Member No.: 7,407 Region Association: None 
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QUOTE(carcus @ Oct 26 2016, 08:55 PM)  Brakes sucked when I got the car, leaking caliper, bad master. Got all new wheel bearings, new rotors, pads, master. No leaks in the system. I have to mash the brake pedal down and it still takes lots of effort to stop. My last 914 was not like this. The mechanic adjusted them but think he forgot to check the pedal adjustment. Any tips to this? Am I missing something. This is about the brake pedal movement to stopping the car. Even at a red light I need to use alot of pressure to keep the car from rolling. The brake pedal should not have that much effort. Really makes the car not fun to drive. And there is really no bite to the calipers to slow it down if I have to slam on the brakes. What break pads are you using and were they bedded in properly? |
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| DRPHIL914 |
Oct 27 2016, 09:52 AM
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#4
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Dr. Phil Group: Members Posts: 5,758 Joined: 9-December 09 From: Bluffton, SC Member No.: 11,106 Region Association: South East States
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I have a 19mm MC and I do not have an issue at all with stopping or having to apply that much pressure- calipers were rebuilt by PMB performance, I installed everything but had issues bleeding them- you have to adjuste the venting clearance in the rear and then bleed them - I got help with that from local PCA member and aircooled shop here and they grab hard and stop fast now!!!
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| McMark |
Oct 27 2016, 11:53 AM
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#5
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914 Freak! Group: Retired Admin Posts: 20,179 Joined: 13-March 03 From: Grand Rapids, MI Member No.: 419 Region Association: None |
Clarification- Does the brake pedal move a little or a lot?
I suspect, from your wording, that the pedal moves quite a bit before it does anything. If I'm right and that's true then you have air in the system and you need to bleed the brakes more. For whatever reason, 914s are notoriously difficult to bleed fully. |
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| pbanders |
Oct 27 2016, 12:00 PM
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#6
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Senior Member Group: Members Posts: 939 Joined: 11-June 03 From: Phoenix, AZ Member No.: 805 |
From my experience, bleeding 914 brakes and getting all the air out of the proportioning valve borders on being an art form. I could never get it to where I wanted it. It wasn't until I had a mechanic here in Phoenix (Jack Doverspike at Stuttgart Southwest) do a full brake job and bleeding that I ever had a really firm brake pedal. How does he do it? No idea, but I'll bet there are people here who can give you a foolproof procedure that completely purges the system of any air.
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| carcus |
Oct 27 2016, 12:26 PM
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#7
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Member Group: Members Posts: 223 Joined: 16-March 16 From: Colorado Springs Member No.: 19,760 Region Association: Rocky Mountains |
QUOTE(McMark @ Oct 27 2016, 11:53 AM) Clarification- Does the brake pedal move a little or a lot? I suspect, from your wording, that the pedal moves quite a bit before it does anything. If I'm right and that's true then you have air in the system and you need to bleed the brakes more. For whatever reason, 914s are notoriously difficult to bleed fully. The brake pedal does not go down that far. There is not that great brake bite. You really have to push the pedal hard with a quick stop. |
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| carcus |
Oct 27 2016, 12:27 PM
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#8
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Member Group: Members Posts: 223 Joined: 16-March 16 From: Colorado Springs Member No.: 19,760 Region Association: Rocky Mountains |
QUOTE(Dave_Darling @ Oct 26 2016, 10:22 PM) Get rid of that Mercedes 23mm master cylinder. Switch back to a 914 17mm one. Actually, I'm guessing you have a 19mm one? The 17mm one will require about 25% less effort for the same stopping force. Also check that the floor that the master cylinder bolts to isn't flexing--McMark and Racer Chris both make braces to help keep the MC from moving. And check your brake lines when someone stands on the pedal. --DD I had a 19mm one that I bought from Auto Atlanta but it leaked. It was replaced with a 17mm one I believe. |
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| Cracker |
Oct 27 2016, 01:34 PM
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#9
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Advanced Member Group: Members Posts: 2,148 Joined: 2-February 10 From: Atlanta (area) Member No.: 11,316 Region Association: South East States
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From the sound of it I believe you have a faulty MC...with a 17mm MC the pedal should be very compliant.
Tony |
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| carcus |
Oct 27 2016, 02:52 PM
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#10
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Member Group: Members Posts: 223 Joined: 16-March 16 From: Colorado Springs Member No.: 19,760 Region Association: Rocky Mountains |
QUOTE(Cracker @ Oct 27 2016, 01:34 PM) From the sound of it I believe you have a faulty MC...with a 17mm MC the pedal should be very compliant. Tony The first one was faulty and leaking. This is another one I had to replace it. I would think 2 bad ones would be kinda rare. There are no visible leaks in the system and the fluid is full. Auto Atlanta mentioned it might be the flex lines. I have not replaced them. I am trying to send the first leaking master cylinder back to Auto Atlanta in exchange for some new flex lines. I will then have those replaced and the system bled again to see if issue is fixed. Auto Atlanta has always taken care of me in the past. |
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| TheCabinetmaker |
Oct 27 2016, 03:02 PM
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#11
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I drive my car everyday Group: Members Posts: 8,300 Joined: 8-May 03 From: Tulsa, Ok. Member No.: 666 |
Nice job. If that doesn't spark a debate nothing will.
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| stugray |
Oct 27 2016, 04:44 PM
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#12
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Advanced Member Group: Members Posts: 3,824 Joined: 17-September 09 From: Longmont, CO Member No.: 10,819 Region Association: None |
QUOTE(carcus @ Oct 27 2016, 02:52 PM) Auto Atlanta mentioned it might be the flex lines. I have not replaced them. ... in exchange for some new flex lines. I will then have those replaced and the system bled again to see if issue is fixed. If your flex lines are restricting the flow so much that it is making a "hard pedal" then they are restricted enough to cause the calipers to bind after release. Jack up one end of the car and spin a wheel and press the brakes. See if the brakes grab abruptly or slowly. Then once they have grabbed, release the pedal and see if they release immediately. |
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| Dave_Darling |
Oct 27 2016, 05:06 PM
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#13
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914 Idiot Group: Members Posts: 14,981 Joined: 9-January 03 From: Silicon Valley / Kailua-Kona Member No.: 121 Region Association: Northern California
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How is the clearance adjustment on the rear pads?
Use half of the spec; I suspect the published number is intended to be "total clearance" and not "per side". --DD |
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| Mike Bellis |
Oct 27 2016, 05:45 PM
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#14
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Resident Electrician Group: Members Posts: 8,345 Joined: 22-June 09 From: Midlothian TX Member No.: 10,496 Region Association: None
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You are within a few hours drive to PMB. Take it there and have them fix it.
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| jcd914 |
Oct 27 2016, 06:03 PM
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#15
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Advanced Member Group: Members Posts: 2,081 Joined: 7-February 08 From: Sacramento, CA Member No.: 8,684 Region Association: Northern California |
Years ago, I replaced the brake pads (frt & rr) on a 914 and the car just would not stop well. The pedal feel was fine, no air, no slop, nice firm pedal when you stepped on it.
The pads were a no name brand, came in plain white box (we had a service manager that kept trying to save a buck or two) and they just had no bite to them. I went thru the bedding in process, still no good. I finally convinced the Service Manager that we needed to put in different pads. I swapped the pads out for some Textar pads and we had good brakes again. Jim |
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| zipedadoo |
Oct 27 2016, 06:22 PM
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#16
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Member Group: Members Posts: 135 Joined: 23-January 14 From: Arizona Member No.: 16,921 Region Association: None |
Does your parking brake work ?
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| 6freak |
Oct 27 2016, 07:33 PM
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#17
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MR.C Group: Members Posts: 4,740 Joined: 19-March 08 From: Tacoma WA Member No.: 8,829 Region Association: Pacific Northwest |
you can compress air but not brake fluid there for i dont think its an air issue,,peddle dont move as designed its the MC or peddle gluster.IMO..did you bench bleed the MC to make sure it actually worked before install....dont say its new hahaha the other one didnt work out for ya..id start at the peddles its that or next in line...JMO good luck
(IMG:style_emoticons/default/smile.gif) |
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| carcus |
Oct 27 2016, 09:53 PM
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#18
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Member Group: Members Posts: 223 Joined: 16-March 16 From: Colorado Springs Member No.: 19,760 Region Association: Rocky Mountains |
QUOTE(zipedadoo @ Oct 27 2016, 06:22 PM) Does your parking brake work ? Parking brake works well. |
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| carcus |
Oct 27 2016, 10:01 PM
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#19
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Member Group: Members Posts: 223 Joined: 16-March 16 From: Colorado Springs Member No.: 19,760 Region Association: Rocky Mountains |
QUOTE(6freak @ Oct 27 2016, 07:33 PM) you can compress air but not brake fluid there for i dont think its an air issue,,peddle dont move as designed its the MC or peddle gluster.IMO..did you bench bleed the MC to make sure it actually worked before install....dont say its new hahaha the other one didnt work out for ya..id start at the peddles its that or next in line...JMO good luck (IMG:style_emoticons/default/smile.gif) I did not do the install myself. It was done by a local mechanic. The first failed MC was sent back to Auto Atlanta today and the braided lines will be coming soon. I will take it this time to a brake specialist and get it looked at. Snow season is coming so the car will be under a cover when the snow falls and I will work on it after the season ends. I have bedded in several cars brakes before and know how to do it. I do not think it is a disc or pad issue. I understand these are not power brakes but there is no difference when I got the old seized rear caliper off and had a pair of rebuilt rear calipers installed with the new brake parts. It could be an adjustment issue as well. Right now I have pretty much replaced everything. |
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| carcus |
Oct 27 2016, 10:04 PM
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#20
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Member Group: Members Posts: 223 Joined: 16-March 16 From: Colorado Springs Member No.: 19,760 Region Association: Rocky Mountains |
QUOTE(carcus @ Oct 27 2016, 10:01 PM) QUOTE(6freak @ Oct 27 2016, 07:33 PM) you can compress air but not brake fluid there for i dont think its an air issue,,peddle dont move as designed its the MC or peddle gluster.IMO..did you bench bleed the MC to make sure it actually worked before install....dont say its new hahaha the other one didnt work out for ya..id start at the peddles its that or next in line...JMO good luck (IMG:style_emoticons/default/smile.gif) I did not do the install myself. It was done by a local mechanic. The first failed MC was sent back to Auto Atlanta today and the braided lines will be coming soon. I will take it this time to a brake specialist and get it looked at. Snow season is coming so the car will be under a cover when the snow falls and I will work on it after the season ends. I have bedded in several cars brakes before and know how to do it. I do not think it is a disc or pad issue. I understand these are not power brakes but there is no difference when I got the old seized rear caliper off and had a pair of rebuilt rear calipers installed with the new brake parts. It could be an adjustment issue as well. Right now I have pretty much replaced everything. One more thing, when I got the rear calipers, I did get the rubber brake hoses replaced at the same time. Just so confused. I still thing it might be a bleeding or adjustment issue. I have spent way too much money on brakes when I need to get the body work done and pan replaced. |
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