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davidhasper · Joined: 28 Jan 2005 Posts: 6 Location: NH

My brake pedal had gone soft over a couple of days and the braking power has been cut to a quarter. I parked the car and a friend said I may have air in the lines. How does air get in? A hole? Can I bleed the brakes by myself? Is there a website that has instructions?

maireeka · Joined: 29 Aug 2004 Posts: 299 Location: North Alabama

On other cars I've worked on, it's been pretty straightforward. To bleed at the calipers, you locate the bleeder valve on the caliper or drum. Attach a piece of EFI type hose to the valve and place the other end in a bottle of brake fluid. Loosen the valve. Then, have someone pump the brakes while you hold the hose in the bottle, watching for bubbles in the fluid. When there are no more bubbles, tighten the valve, remove the hose, and move on to the next caliper. It's important to start with the caliper furthest from the Master cylinder and work your way toward it. RR LR RF LF is the order.

I hope this helps, and please correct me if I'm wrong anyone!

Patrick
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1977 Porsche 924 red and READY!

924guy · Posted: Sat Jan 29, 2005 1:50 pm Post subject:

before you do anything inspect your brake system and look for fluid leaks, especially around the calipers (drums if youve got em) and master cylinder area. if any spots look stained, gunked up, or otherwise contaminated, clean that area, pump the brakes a few times and look for "fresh" signs of leakage.anyplace fluid can bleed out, air can get in... when in doubt, replace the suspect part or line, brakes are nothing you want to be cheap on or take risks with. If that looks okay, then you can move on to the bleeding/fluid change . chances are the brake fluid in your car is old, and the system hasnt been flushed in some time ( i generally do mine once a year if i do allot of driving, or every two years if i dont use the car that often.) before you start trying to loosen brake bleeder screw, give each one a good squirt with pbblaster or similiar , especially if they havent been touched in a long time. the last thing you want is a broken brake bleeder screw. let em soak in the stuff, or reapply it for a few days in a row to help limit the chances of breaking one when you do have to loosen them up.
as mentioned above, the old method of pumping the pedal will work, but it does take two people, and its tiresome.. Id highly recommend you invest in a power brake bleeder or a mightyvac. its well worth the price and with the mighty vac, you can use it for allot of other testing and fluid transfer missions as well.. Itll cut the time for the job by 3/4's of what itll take to do it manually, no 2nd person required.
with the mightyvac, all you do is set up the lines, pop the hose on the bleeder, pump it a few times to build vacuum, and crack the bleeder. itll draw out the old fluid and the crap in the lines. be sure to keep an eye on the master and refill it often with a good quality brake fluid. i use valvoline sythetic (wear gloves,itll suck the moisture out of your hands and prune them up to the point of pain if you get too much on you) but any parts store will carry some better fluid, please ignore the 99 cent a quart stuff..get at least 2 quarts btw, and fully flush the system. your doing it anyhow, wont take much more effort to keep on unitl not only all the air is out, but the fluid runs clean. close the bleeders when you dont see any more airbubles, while its running out (so it doesnt suck air back in.) if your doing it by pedal pumping, close them on the downstroke of the pedal. repeat this process at each wheel. once your done there, give the pedal a few more pushes , top off the master..and if youve done it right, you should have a nice firm pedal. then start the engine to build vac pressure and pump it again. itll be a little bit softer, but shouldnt be too much so. if it gets really soft, start bleeding again until its not..
once you get the hang of it, its fairly easy, and well worth the effort, but do yourself a favor and get the power bleeder, without it, it can take a long time to get it right..
_________________
Eric
78 924
82 931 SE "smokey"
99' VehiCross
Y2K Honda Insight
http://www.cardomain.com/id/924Guy
Performance by Pasha

jpab924 · Posted: Sat Jan 29, 2005 3:52 pm Post subject:

If the pedal goes to the floor....I`d suspect the master cyl. if the reservoir is full. Air just doesn`t happen to get into a hyrdraulic system. Unless is a component was replaced.

Calipers should also slide freely....

My 9 yr old daughter can bleed brakes.

Pump `em` Hold `em` always works for me.

CMXXXI · Joined: 05 Nov 2002 Posts: 1939 Location: Vicksburg, MS

Let's not forget that if we are talking drum brakes on the rear, they are not self-adjusting. How many times have we been reminded that you will lose your braking power unless you adjust the rear drums. Although bleeding the system is a simple task, I'd suggest double checking to ensure the drum brakes are properly adjusted.
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'79 Eurospec 931

jpab924 · Posted: Sat Jan 29, 2005 4:36 pm Post subject:

You know, I see your point....but drum brakes will not lose their adjustment over a couple of days.

But non-the-less, this would be a good place to start if you have rear drums.

Paul · Posted: Sat Jan 29, 2005 9:11 pm Post subject:

If your rubber brake hoses are more than 10 years old, replace them!

davidhasper · Joined: 28 Jan 2005 Posts: 6 Location: NH

I seem to have a battery problem too so I can go through all of your suggestions, thank you. I'll check back when I figure out the over all condition of the brake system.