Home 
Home Search search Menu menu Not logged in - Login | Register

 Moderated by: Greg Fletcher Page:  First Page Previous Page  1  2   
New Topic Reply Printer Friendly
Mushy brakes  Rating:  Rating
AuthorPost
 Posted: 05-18-2011 05:58 pm
  PM Quote Reply
21st Post
mcguan.2
Member
 

Joined: 12-13-2007
Location:  
Posts: 42
Status: 
Offline
Jody,

Any particular brand of DOT 5 fluid I should use?  Also, what's the capacity of the system, i.e. how much should I buy?

Back To Top PM Quote Reply  

 Posted: 05-25-2011 04:32 pm
  PM Quote Reply
22nd Post
JodyKerr
Member


Joined: 05-15-2006
Location: Tempe, Arizona USA
Posts: 217
Status: 
Offline
no particular brand, I've used a couple different ones. I don't remember the fluid capacity of the brakes. I buy stuff in volume because of the number of cars I work on. Accounting for bleeding, I'd hazard 2 bottles should be sufficient.

Back To Top PM Quote Reply

 Posted: 05-25-2011 06:45 pm
  PM Quote Reply
23rd Post
Greg Fletcher
Administrator


Joined: 03-11-2005
Location: Lake Nacimiento, California USA
Posts: 430
Status: 
Offline
Just my 2 cents and based on my specific experience- rebuilding, reboring, resleeving (in brass, stainless, it doesn't seem to matter) or or whatever else you can do to an old master cylinder is a fool's errand. I've done them all multiple times over the years and they have ALL ended with what I can only describe as premature failure and money not well spent. This failure rate varies from less than 1 minute to less than one year of normal driving. On three completely different occasions (using different rebuilt master cylinders), this resulted in catastrophic brake failure meaning I had no brakes to stop the car. This is not a fun feeling and I would recommend you keep the brake system up to scratch and keep it safe by avoiding rebuild masters. Again, your mileage may vary, this is simply my experience with the brake system on the Jensen Healey that an owner is well ahead in installing a new master cylinder. A master cylinder on any vehicle should always be considered a consumable item.

Back To Top PM Quote Reply  

 Posted: 05-28-2011 02:08 am
  PM Quote Reply
24th Post
mcguan.2
Member
 

Joined: 12-13-2007
Location:  
Posts: 42
Status: 
Offline
OK, so I installed the new master cylinder (the TR6 model) and changed over the brake fluid to DOT 5.  However, I'm still getting a little bit of leakage right behind the MC, where it meets the booster.  Did I miss some sort of O-ring or something?  It did seem a little weird how the two just seem to "go together" without any sort of seal. 

Back To Top PM Quote Reply

 Posted: 05-28-2011 02:14 pm
  PM Quote Reply
25th Post
Brett Gibson JH5 20497
Member
 

Joined: 03-17-2005
Location: Hilton, New York USA
Posts: 798
Status: 
Offline
No seal there, sounds like your new master cylinder is leaking.

Brett

Back To Top PM Quote Reply  

 Posted: 05-28-2011 03:00 pm
  PM Quote Reply
26th Post
Greg Fletcher
Administrator


Joined: 03-11-2005
Location: Lake Nacimiento, California USA
Posts: 430
Status: 
Offline
These Lucas units have old school rubber based seals inside and are designed to use mineral based fluids. I don't recommend the use of synthetic brake fluid in a JH system for this reason.

Back To Top PM Quote Reply

 Posted: 05-28-2011 09:09 pm
  PM Quote Reply
27th Post
mcguan.2
Member
 

Joined: 12-13-2007
Location:  
Posts: 42
Status: 
Offline
Greg, understood, but wouldn't it be strange for a brand new MC (purchased from the club store) to start leaking within minutes of installing?  I completed this whole project yesterday, and literally as soon as I took the JH for a test drive, the MC started leaking out the back.  To me, that would seem more like a faulty piece of equipment than a seal failure due to using a synthetic fluid. 

Has anyone else had anything like this happen?

Back To Top PM Quote Reply  

 Posted: 05-29-2011 04:20 pm
  PM Quote Reply
28th Post
LambandAndy
Member


Joined: 10-21-2005
Location: Eastanollee, Georgia USA
Posts: 72
Status: 
Offline
Are you sure that fluid from your old master cylinder didn't leak into the brake booster and that is what you are now seeing leaking out?

Andy

Back To Top PM Quote Reply

 Posted: 05-29-2011 04:28 pm
  PM Quote Reply
29th Post
Greg Fletcher
Administrator


Joined: 03-11-2005
Location: Lake Nacimiento, California USA
Posts: 430
Status: 
Offline
It shouldn't leak, some people can get it to work with DOT 5 and have no problems, but putting in the fluid recommended by the manufacturer is usually a safe bet. Take a look at the box or the instructions that came with the unit. They usually say what fluid is required, some actually say DOT 5 with void the warranty- it depends on the brand. I would try draining the system, replacing with DOT 3 or 4 and do a complete flushing and see how it works.

Back To Top PM Quote Reply  

 Posted: 05-30-2011 02:45 pm
  PM Quote Reply
30th Post
JodyKerr
Member


Joined: 05-15-2006
Location: Tempe, Arizona USA
Posts: 217
Status: 
Offline
How much is "a little"?

And what colour is it?

purple = dot5, dirty/brown = old fluid.

Back To Top PM Quote Reply

 Posted: 06-26-2011 12:40 am
  PM Quote Reply
31st Post
mcguan.2
Member
 

Joined: 12-13-2007
Location:  
Posts: 42
Status: 
Offline
It's really hard to tell what color the fluid is because it's not coming out in copious amounts, just seeping out. I've been driving it around to see if it was doing as you suggested and just coming back out from the booster side (from the previous MC failure) and it's still coming. It does not appear to be dirty fluid, though, which suggests that it is the new fluid.

I put a white napkin under the booster, but like I said, it just seems to be in such small amounts that it's "clear" if anything. I thought that if it was just residual coming out of the booster, that it would stop after a few drives, but that doesn't seem to be the case. I'm trying to strategize my next move. If I have time tomorrow, I might do as Greg suggested and just empty it all out and try again with DOT 4.

Back To Top PM Quote Reply  

Current time is 11:56 pm Page:  First Page Previous Page  1  2     
> Jensen Healey & Jensen GT Tech > Brakes > Mushy brakes Top




UltraBB 1.172 Copyright © 2007-2011 Data 1 Systems