my car is 90 crx si,

my brakes have had some symptoms of a master cylinder going bad possibly, they work and most of the time don't even feel that different, but occasionally they sink or go soft losing pressure, and fine if you just pump the pedal couple times.

car has 234,000miles and never had master cylinder replaced that i know of (i'm second owner, bought car at 111,000 miles and they had all records from services etc..., and i've had car 13 years)

i am not just going to assume its the master cylinder and just replace it yet, first i want to do some tests to help narrow it down a little more.

i went through the brake diagnosis steps that were in the HELMS manual, (i copied & pasted the steps exactly how they were in the HELMS below), and i wrote the result that i got under each of the diagnosis steps

i was hoping people can help me narrow down my brake problem by reading the results i got for each of the diagnosis steps below, and give your thoughts & opinions on what you think it sounds like to you so far ???




Functional Test
------------------------
1. with engine off, depress brake pedal several times, then depress pedal hard and hold pressure for 15 seconds.
if pedal sinks, a brake line, a wheel cylinder or master cylinder is faulty.
-------------------------

[MY RESULT:]
it did'nt sink, had a little hard pressure, not soft, spongey or dropping toward the floor though....



2. start engine with pedal depressed, if the pedal sinks slightly, the vacuum booster is working.
if pedal height does not vary, the booster or check valve is faulty.
----------------------

[MY RESULT:]
it did'nt sink at all, height did'nt change



Leak Test
----------------
1. depress brake pedal with engine running, then stop engine.
if pedal height does'nt vary while depressed for 30 seconds then the vacuum booster is ok.
if pedal rises, the booster is faulty.
--------------------

[MY RESULT:]
the pedal height did'nt change



2. with engine off, depress brake pedal several times using normal pressure, when the pedal is first depressed, it should be low.
On consecutive applications, pedal height should gradually rise.
If pedal position does'nt vary, check the booster check valve.
------------------

[MY RESULT:]
pedal height did'nt go low at first, did'nt rise more with each press either, it was just sort of similar throughout, with nothing really consistent




any info, direction, thoughts or opinions would help me out, thanks

 

sounds like your check valve is faulty?

 

would it be better if my only problem was a bad check valve instead of it being a bad master cylinder ???
to be honest, i really don't know what the check valve does and have never heard of it, and is it hard to replace or expensive???, what would be involved really ?

 

i wanted to run this across some people, get their opinions on if i should try what this guy said to do?,

i was at an autoglass shop yesterday cause i needed new window, and the tech guy said he likes CRX's.
he only drove my car from the front lot around to the back of the shop, but he seemed to know a bunch just from driving it that short distance,

he listed a few things about my car's condition, like "your clutch is good", and he said "your brakes are good,........ they just need to be pressurized, ..... and said "take cap off brake fluid resorvoir, and pump the pedal a few times and get air out or something to that effect ??? (can't recall exactly how he worded it?)

i told him people online have been telling me i'm having symptoms of a bad master cylinder, but he said, "they seem good",

also another time a mechanic friend said that "they seem to have pressure", and to just bleed the brake system & put new fluid etc...

so should i take the cap off and pump the pedal or something like that???, does anyone know what he might of said for me to do, in order to "pressurize it"??, cause i want to try any ideas i can get.

thanks

 

so if my check valve is bad then, what do i need to do now ?, replace it? anyone help what my next step should be?, i'm just trying to do everything i can do before having to take it in to brake shop and pay for stuff to be done. thanks

 

Is recommend bleeding the brakes it's not a hard job to do and it's inexpensive

 

yeah, bleeding brakes was the next thing i was going to do and i was going to try doing it this way i saw on a youtube video for "one-man brake bleeding", at this link: http://www.youtube.com/watch?v=Uvyzt...eature=related

the guy had a jar with hole in top with hose going to it, other end of hose went to bleeder valve and did one wheel at a time, pressing pedal himself & watching the air coming out the hose into the jar. it looked good to me, but was wanting to see what people on here thought, and if theres anything i need to know before getting started, like any special tricks? or something i need to know??

cause i saw a post on this site where guy said this :

"as for 1 man brake bleeding jobs, no, you cant pump the pedal and close the bleed screw all by yourself. when the pedal springs back, it sucks the displaced volume back in, either the old fluid you pushed out, making pushing pointless, or air, which is why you have to close the screw before you lift the pedal. speedbleeders has some satisfied customers which makes quick 1 man bleeding, but really, is it that hard to find someone to help you out for 30 minutes to pump the pedal? and i dont recommend using a mityvac. it doesnt seal properly around the bleed screw."

any thoughts, thnx

 

harbor freight has brake bleeders for liek $15 or something. i have 1. works great.

 

i used the one man bleeder method when i replaced my drivers rear caliper last weekend, worked GREAT. the check valve is the whit plastic thing in the middle of the line between the master cylinder and the intake manifold. it's held in the line with two hose clamps, quite easy to replace. might want to replace the line as well, as it does get old and cracks

 

can you tell me, is the brake bleeder you got at Harbour Freight the type that lets you bleed the brakes by yourself ?, like a "one-man job" ??

if so, then i might be interested and go by to get one later., thnx