1973 Porsche 914 Brake and Sway Bar Problem

Cire · 03-11-2009, 07:26 AM

Howdy Everyone,

I have encountered 2 problems I could use some help with. The first issue are the brakes. Its a new (to me) car and I am going through it and making sure everything is working correctly. Anyway, the brake pedal was mushy so I figured I would go through and bleed the brakes as normal. The 2 fronts went great. No air and brake fluid came out as normal. I went to the rear and both brakes didnt get any fluid through them. Even when pumping and holding no brake fluid came out of the line. So I disconnected the 2 lines that lead to the rear brakes and blew a little (not direct) air through them and it blew through without any problems. I squirted some WD40 in both lines and blew them out and even squirted some brake fluid through to make sure they were clean. Anyway, with the lines disconnected I pushed on the brake pedal to make sure that brake fluid was getting this far... ITS NOT! I didnt know if the 914 had a flow regulator valve that you could do more braking up front or adjust the braking conditions in the car. What are your all thoughts? Here are pictures of the brakes as well as the junction spot...

The other issue I have is the sway bar in the rear of the car. Here is a picture of the situatuion. How do I fix this?

Thanks everyone for your support. = )

Eric

conedodger · 03-11-2009, 08:02 AM

Normally, you start bleeding from the furthest bleeder from the master cylinder so you should have been at the left rear, right rear, left front, then right front. Beyond that procedural advice it is hard to tell what is going on here.

The rear sway bars have four little round white bushings that get pushed into that down link at each of the round holes. One of yours has disintegrated. Buy all four and replace them and while you are at it, take a look at the two bushings at the bottom of the body. There is a trick to getting these bushings into the downlinks. I push them in with a vise, others have their ways as well... I then pack the bushing with a little synthetic grease and here is a little trick I learned from McMark at Original Customs, I drill a hole in the middle of the bushing just tiny enough to let the air out when you are trying to get the cup over the ball. I then smack them on with a BFH...

Good luck with your brakes. Try asking over on 914World and be sure to put the words brake bleeding in the title. Eric Shea will know for sure what your problem is...

Cire · 03-11-2009, 09:19 AM

Thanks Conedodger. = )

I tried something a little different. I hooked up a pump to the back of the bleeder bolt and turned it on to help ensure the lines had liquid in them... It wouldnt pull any brake fluid through the lines. I even pressed the brake pedal a few times with the pump running and nothing came through.

My thought is that proportioning valve. It seems like its all stopping right there. It could be that I have checked everything back to that point as well. What about a master cyl going bad... But if the front brakes bled correctly last night, I would think the master is working.

Another thought... I was going to route the rear line down to the front line connection pump and pump the brakes and see if that junction would feed brake fluid to the brakes.

Again thanks for all the ideas and help. = ) Greatly appreciated.

Jared at Pelican Parts · 03-11-2009, 09:57 AM

Sounds like the proportioning valve is clogged/shot. You don't really need it all that much on a street car anyway. Just get a metric T-fitting and you'll be set. I'd also reccommend upgrading the master cylinder to the 19mm unit out of the 911 if it hasnt already been done. Be sure to flush ALL of the old fluid out of the lines.

Cire · 03-11-2009, 10:35 AM

Thanks Jared for the Info.

I took off the line that goes from the fire wall to the proportioning valve and it too seems to not be getting brake fluid. Another interesting item is that this brake fluid seems thick. Could just be cold. Could just be me not playing a lot with brake fluid. Just an observation. = )

So whats next? Where does it go from the fire wall? To the master cylinder? Can you only get to the master cylinder by taking out the gas tank and all that stuff? I guess once your there you change out the master cylinder to the 19mm unit you mentioned above?

Wow. Are brakes all that needed? = )

Thanks again. Here are a few more pictures of what we are looking at.

Eric

Jared at Pelican Parts · 03-11-2009, 10:38 AM

You have water in the brake fluid. i.e. the muck.

If you arent getting fluid flow at that line, i'd say the master cylinder is probably shot. Changing it isnt too hard. You do it from uinder the car in the front. There is an access panel that comes off. No need to remove the tank, which wont help you as there is a bulkhead under it. I'd be soaking up all of that spilled fluid as well. It will ruin the paint.

Cire · 03-11-2009, 10:44 AM

Anyone have any pictures of the access panel? = )

Thanks again Jared. I will go take a look.

Eric

Cire · 03-11-2009, 11:11 AM

As the Rotor turns...

I did some looking around, found the access panel on the bottom of the car, unbolted the 2 bolts and folded it down to expose the steering rack and the master cylinder. I decided to test it a bit before taking it all apart. I took off the fitting on the right (towards the front of the car) and it ran clean and nice like brake fluid should. I then took the one that fed the back brakes and ... nothing came out. Not a drop. Again I blew a little air through the brake line going backwards and it blew out right where I took off that other short brake line fitting at. Finding that strange to not even get any fluid out of it, I went to the top and checked the resevour. 100% topped off just like it was this morning when I started this... But I have drained a lot of fluid... Shouldnt some be gone?

Problem now... How is the master cylinder fed from the brake fluid resevour??? Could that be the problem? No fluid to get to the back brakes? .... Scary part. I drove the car and it was great. = )

More pictures of where we are at thus far.

Eric

Cire · 03-11-2009, 11:58 AM

And it keeps on comin.. = )

I got all the lines disconnected and the Master Cylinder out. The two lines that go to the top of the master cylinder are blocked? pluged? Stuck? Something that stops it from getting fluid. Thats why the front worked and the rear didnt. Front got fed first.

So... Why are they pluged? Is this the common issue when a master cylinder goes out on a 914? Maybe it was a little water in the line and they rusted shut?

Can it be fixed or is it a replace part? These days my budget is pretty tight. If I could fix this and drive the car I would rather do that then buy a new one. If the fix is 100 and the new one is 105, then we would just the new one. If the fix was 10 and the new one 250... Easy choice too.

Here are some more pictures. I hope this helps folks down the road that are having issues with brakes.

Eric

Jared at Pelican Parts · 03-11-2009, 12:01 PM

Check the reservoir.

jhora · 03-11-2009, 12:43 PM

Hey Eric (Cire)....please do this right away....go and buy yourself some real jack stands to use on your 914....
please....please don't get under that car with the wooden blocks under the wheels and the plastic milk crate supporting it

even though your hydraulic jack is under it....
you can get two stands at Harbor Freight for $20.. http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=38846
SAFETY MAN SAFETY!
we want you here reporting your great progress for a long time
.....Regards...John

Cire · 03-11-2009, 03:32 PM

You are right John. I need another set. What you dont see is that the rear end is on my 2 jack stands. So it cant roll or go anywhere but you are 100% correct. I need some and will get some. = )

Also, for everyone who has been reading this, there is an interesting end (does it end...) to the story. I started looking at 19MM Master Cylinders and saw that some where up near the $200 dollar range. Being a depression (hang on, we are getting there) I need to save some money. So I decided to look at the Master Cylinder I had that was bad and see if I could see something wrong. Took it all apart. Cleaned it up. I was looking at the 2 rubber things on top and thought that that location is what gets fed from the resevour. So I pulled out the rubber grommets and what did I see.... OH MY GOSH!!!! A damn little flake of tin foil from one of the tops of a brake fluid bottle. YEAH!!! NO KIDDING!!! I know many of times when I personally was not -real- carefull with the tin foil lid on the bottles of brake fluid... NEVER AGAIN!!!! LOL

Here are some pictures... A tiny flek can cause so many hassles.

Eric

jhora · 03-11-2009, 07:22 PM

That is really crazy....I too will be more careful the next time I open a bottle of brake fluid...
glad you had it up on some stans...didn't mean to sound like a safety lecture....just don't want anyone to get hurt...
great job!

Jared at Pelican Parts · 03-12-2009, 07:43 AM

WOW!

Thats another first for the 914 forums, lol. Thanks for the pictures!

Cire · 03-12-2009, 08:33 AM

Just to follow up on things...

I pulled out the tin foil, cleaned it all up, put it back in the car, filled it with brake fluid.... Works great! = ) Shot me over a piece of tin foil. LOL

Thanks everyone for the help. I cerntainly have a better grasp on the 914 braking system. = )

Eric

jhora · 03-12-2009, 08:36 AM

Outstanding....glad you got it back in and working...now go drive that thing