308 Right Front Brake doesn't work

The brake hose is probably plugged. Remove the hose and check the flow through it. You can check the flow of fluid from the brake pipe leading to the hose.

It is strange the the car pulled to the right if the right brake was not working. If a brake is not working it will pull to the side that has the functioning brake, as that is the side that is slowing down.

 

If you find the clog is not in the hose, and even the solid line does not give fluid, try removing the hard line from the master cylinder itself. Then pump the brakes, see if it squirts clean. I've seen many cases where 2 channels of a 4 channel master cylinder don't squirt fluid, just a bad master cylinder. I'm not familiar enough about the 308's brakes to speak as to how many channels it has, but it's likely that's not the only one down, so be sure to check that all 4 are working. (It could be RF and RR gone, RF and LR gone) As always, bleed well! Good luck.

 

Time to replace ALL the brake hoses.

They swell internally and stop the flow.

About a 99% chance that this is the problem.

 

Just did this on my car. Info on what to buy at the end of this thread:

http://www.ferrarichat.com/forum/showthread.php?t=165853

 

It sounds like the left front piston in the caliper is stuck, this is common when the car left to sit for long periods of time. Ferraris LOVE to be driven NOT stored.
Personally, I'd flush the brake fluid and then open the brake bleeder screw and gently force the pistion back manually using a large screwdriver etc., that should free it up, else it's time to clean and rebuild the caliper.

 

You are not paying attention.

Read the thread, this is NOT the problem.

 

10 years? You could have a blocked hose AND a stuck caliper -- Good luck with the "reawakening"...

 

Replacing the front lines is a bit of a challenge. I put the Brembo kit on mine back in 03 and I seem to remember that loosening the inside part of the old line was an excercise. Not a lot of room in there to turn it or something. It is probably a lot easier if you are not lying on your back with the car on jackstands at night in the driveway, though...

 

I know your pain but I am so done with the jackstands in the driveway BS! My new lift paid for itself on this job alone No cussing or loss of blood! The front lines are much easier to replace if you can get the car up in the air. If you are going to work on your car regularly, consider this:

http://ferrarichat.com/forum/showthread.php?t=160439

 

Yes, it is possible that the hose lining separated and is acting like a valve, causing no fluid at all to pass through. But you won't know that for sure until you remove the hose from the hard line and then try to push some fluid through.

One other spot in the system to keep in mind, if you find that after removing the hose you still get no fluid through the pipe. In addition to the pipe itself being clogged, there is a devise in the front of the car, right behind the battery, that senses a pressure differential between the front and rear systems and turns on the brake warning light on the dash. It's a little brass piece, and you will see the line running into and out of it. It's possible that you have a clog in there that is blocking the one line (assuming the other three produce fluid when being bled). While I certainly would check the master cylinder, before you tear things apart, check that valve/sensor unit. And if the right front hard line turns out to be clogged, you only have to run a new one from that valve to the hose (18" or less?).

You can access that valve and the lines that junction there by removing the bottom skid plate. That also makes access to the hose fitting at the right wheel a little easier also. But as Dr. Tom said, getting the front hoses off and back on the inside connection is a PITA. I'm waiting until this winter to change mine, when I pull the suspension out to do the bushings. The rears are a piece of cake by comparison.

 

Just in case you don't have a schematic of the brake system:

The item circled is the device that FasterIsBetter is referring to. Is this not also the proportioning valve?? The parts manual calls it a Brake Failure Indicator.
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Thats a different diagram then I have for my 308. On the line going from the valve assembly to the rear brakes there is a proportion valve. This is preset for rear brake pressure. The valve shown is the diverter valve which has a spool valve inside that shifts based on brake pressure lost in either the front or rear brakes. I had this rebuilt by Whitepost. It is a simple valve but there was not a seal kit available. If you do a search you will find that you can use an early Volvo 240 unit and plug the extra holes. I believe the Ferrari on is NLA. Good luck

 

The valve identified as No. 16 in the upper left corner is the item identified in the red circle in Michael's picture. That is not a proportioning valve. It has no effect on the pressures between the front and rear circuits. If you notice, there are two lines coming out of the master cylinder. The one on the left goes to the rear circuit, and the one to the right goes to the two outlets for the front circuit. There is a little shuttle valve between the circuits that shifts to one side or the other if there is a drop in pressure relative to the other circuit and turns on the brake warning light. That's all that thing does. But it does have internal seals, and if the seals broke down, it is possible that the line leading to the right front brake caliper could be plugged in there. Worth checking IMHO.

 

If the lines were actually clogged that should tell you how often the fliud was changed. I will not be surprised if the calipers won't have to be rebuilt. I can't believe they aren't rusted now. Good luck with everything and keep us posted.

 

Once again, I agree with Dr. Tom. If you do need to rebuild the brake calipers, be aware that they are ATE calipers, not Ferrari, and that the parts are readily available to rebuild them. There are a couple of threads on this, but IIRC, the fronts are the same as the last '70's - early '80's Porsche 914, and the rears are the same as the Porsche 911SC. The kits can be had from some of the usual suspects selling Ferrari parts, or check the prices with some of the Porsche parts distributors on line. But do a forum search and check the parts interchange sticky at the top of the 308/328/Mondial forum. There was a thread on this recently on that forum as well. The only problem with the rears is that you can't remove the adjusting screw, but you can replace the o-rings and seals and the piston.

And while you are at it, you might want to remove that valve in the front and make sure it's clean inside. As someone noted, there is an old Volvo part that can be used to replace that by simply sealing the extra ports. There's a thread on that as well in the 308 forum.

 

By the way, if the car was sitting for a long time and moisture got in there, you could have rust and corrosion in the hard lines. Look at that closely. You may have a nice little winter project there replacing the brake lines.

 

For clarification the rear calipers are identical to Porsche 914-6 and the fronts are identical to 70's-80's Porsche 911SC. See this thread for more info:

http://ferrarichat.com/forum/showthread.php?t=88518&highlight=caliper+rebuild