TR5/TR250 TR250 now has Silicone Brakes but no Clutch! HELP!

[angelfj1]

Rob: yes, several folks have warned me about this, but the slave cyl. is right-side-up. I was wondering, did you find like others that you needed to periodically bleed the brakes and clutch systems because they went spongy?

 

[tomshobby]

Had an unusual thing happen that produced similar problems, one of the bolts for the slave bracket came loose so the plate had flex in it.

 

[pa297pass]

... but the slave cyl. is right-side-up.

FJA:

How do you determine if the slave cylinder is right side up? Is it just that the bleed screw is in the "top" hole, or is it something internal to the cylinder?

Thanks.

Matt

 

[angelfj1]

Rich: Can you provide further details on how to chase down these clearance issues. I have both the Bentley and Haynes manuals. Where would I find these details?

Thanks, Frank

 

[Guest]

.....I just got a phone call from my connection with Valvoline products.... I'm not allowed to use his name, but he is in product research/engineering...... The PROFESSIONAL consensus is.... do not use silicone fluid. Why? Even though the fluid does NOT absorb moisture, moisture still gets into the system (Gee! I hear an echo!) and the water droplets are not absorbed, thus they corrode whatever they contact, and embark on the journey of higher specific gravity toward the lowest point in the system thus exacerbating the problem! (Another echo) Oh, he also enlightened me as to the military use of silicone.... THEY FLUSH THE VEHICLE's brakes systems out frequently!!! Because of this water contamination! WOW!

Now for the final statement!!!!! Retrofitting products into an automobile in areas of possible hazard (Me thinks brakes fit into this category) without the express approval for the use of this product by the manufacturer in THEIR own vehicles is a ludicrous and potentially hazardous endeavor! Just because someone has had no problem with doing this does in no way minimize the inherent, intrinsic potential danger.

It makes me think of a guy that plays russian roulette and never has hit on the chamber with the slug.... it is still very dangerous.

 

[RobT]

Rob: yes, several folks have warned me about this, but the slave cyl. is right-side-up. I was wondering, did you find like others that you needed to periodically bleed the brakes and clutch systems because they went spongy?

Yes - figured you probably had it right but thought it worth asking.

The brakes (not so much the clutch) were a bit spongy at first with the silicone. It improves as you drive the car and work the brakes (I think its probably bubbles working their way out of the M/C) and after re-bleeding the system. As others have said, the silicone is thicker than LMA or other glycol fluids and can take a little while to "settle in". But after that, you are all set for life!

Rob.

 

[RonMacPherson]

Sherm,

even professional opinions will vary... How do I know? Valvoline was our sponsor in Formula Three, I spent some time with the engineers, mostly at track days... A couple there thought silicone for STREET USAGE was the greatest thing since sliced bread.

Carroll Smith, who in my mind was one of the top brake men ever, recommended every one should flush their cars brake system every year, but if that wasn't going to happen use silicone fluid... He also recommended brake flush on race cars, before and after, and some times during every meet....

I have used silicone in 6's since the late 80's, also in Honda Accords(with ABS by the way) and on my Yamaha FJ1200.. Spongy pedal? not for street usage...

Now as for the clutch problem... have you tried a back bleed?
We used to have to do that on older MB's when the clutch just would not bleed.. Use a mity- vac or other time reservoir bleeder, introduce the fluid at the slave cylinder bleed outlet(always making sure that it is the highest point of the slave when regularly bleeding, doesn't matter when reverse bleeding) and pump the fluid up through the line into the master cylinder. Just make sure you have protection under the cylinder when the fluid overfills.

Also, did you pull the cup from the slave to make sure the piston is fully extended. If it is not all the way extended in its travel(towards the pushrod) you will NEVER get the system air free.

 

[Guest]

Your statement just goes to show one thing. A person's mentality is very difficult to influence. I know a young lady that drinks and drives regardless of Texas' laws regarding it that have been made so strict. She feels perfectly capable of handling herself behind the wheel after a night of drinking.

Just as no one can convince her of the potential danger in her decision, it is obvious that you and some others here will not change their minds. And I won't change mine, so all this prattle is for naught.

My guy with Valvoline is really not the only person I wanted to quote, but my guy with Dodge has yet to return my call. (holiday)

As i said before; Silicone is neither used nor recommended by any manufacturer for what ever reason or combination of reasons therein. That, my man is cloaked by wisdom far beyond you, me, or some race dudes, Jaguar genius, or any one who thinks they have THE answer.

I now officially lower my flag on this subject, in as it has become boringly redundant.

 

[Don Elliott]

In 18 years of using silicone fluid in my 1958 TR3A for my brakes and clutch, I have never had any rust develop. I use my TR for normal driving and touring, like most TR owners who write on this forum.

I store my car for 5 or 6 months every winter and have never had any issues with water absorption or rust. Every spring, I start it up and the brake/clutch fluid system is never an issue. The slippery nature of silicone fluid keeps everything well lubricated and I've never had to fiddle with anything - especially the pistons for the front disk brake calipers. They slide in and out like they are on silk.

How is it that there are some people who .....

Well I'd better not say any more about them.

I agree with the race drivers who don't use silicone fluid in their racing TRs. When they want to change the fluid between practice and the race, they don't have three days to let it sit to get rid of the bubbles.

 

[Mickey Richaud]

OK, guys - enough with the "mine's bigger than yours", please!

Frank, have you gotten any answer to your question that you can actually use?

Mickey

 

[angelfj1]

Mickey: yes I appreciate all of the suggestions and I will report back.

Frank

 

[TR4nut]

Frank-

Trying to honor Mickey's well timed group spanking here and not stir the pot -just adding an opinion and clarification. Based on your starting comment that you did not dismantle the clutch setup, I don't think linkage adjustment is the issue. I think you simply have air in the line somewhere. Happened to me with Castrol LMA, for some reason that setup is a real pain to purge.

Silicone fluid is more compressible than glycol based fluids - but if air is not in the system I doubt if you could detect a motion difference. The quotes I've seen are 2-3 times more compressible. I saw a quoted compressibility of 6E-4 vol/vol/MPA or roughly 4E-6 vol/vol/psi for a conventional brake fluid. Assuming a generous system volume of say a quarter pint (standard british beer unit), brake system pressure of 1200 psi, and slave bore diameter of 0.75", you would have a travel difference of roughly 0.05" with the two fluid systems. And I think I'm being way generous with the system volume.

I usually have luck purging the system by getting a friendly assistent to hold down the clutch pedal while loosening the bleed valve. You may have to do that quite a lot to get the issue resolved, but I will stick with my bet that it is trapped air.

Randy

 

[TheSearcherMan]

I wish I had used silicone in my TR6, but didn't due to the horror stories I heard while doing research. The clutch can be tricky to bleed using conventional brake fluid, even more so with silicone. I use a clear hose on the slave bleed fitting, put the other end into a jar of brake fluid, just barely crack the bleed fitting on the slave cylinder. Then, take a stick and push the clutch down and watch the air go thru the hose, into the jar. It is tricky to get all the air out of the clutch, don't give up. It is easier with 2 people than the stick I use by myself. I use silicon in my motorcycle brakes, and it works great, and the lever is solid. My motorcycle is a 74 Norton, and it does not leak either, and it been about a year and a half. It just takes patience to get the air out. To the best of my knowledge, Harley Davidson has used silicone in all their new motorcycles for years, they would not do this if there was a problem.

 

[angelfj1]

thank you all for the suggestions - tomorrow night will be the acid test!

 

[Mickey Richaud]

thank you all for the suggestions - tomorrow night will be the acid test!

<span style="font-size: 26pt"> NO! </span> Don't use ACID!

 

[Rich_M]

I'm the guy who posted about my experience with linkage adjustments...

Per Frank's question, the manual I'm using is the original "Service Instruction Manual TR2..Incorporating Supplement for TR3 Model" It was issued by Standard Triumph and I think high quality reprints are available from many of the TR parts suppliers.

I agree with Randy's logic about linkage adjustment not being an issue.

Further, my manual actually says: "The adjustment connection between pedal and master cylinder is set on initial assembly and should not need re-adjustment."

Certainly, messing with these adjustments could make things worse. That said, sometimes problems seem to defy logic and, in my case, the adjustments seemed to fix my problem.

The proceedure isn't complicated and it takes up about a page in the manual. I'd e-mail it to you, but I don't have a scanner. If you can get a hold of this manual, the procedure is in Section D (Clutch), page 4-5 (subsections 13-15). The procedures cover both clutch and brake master cylinders and the clutch slave cylinder.

Also note that I'm making a guess here that the TR250 has essentialy the same clutch/brake setup as the TR3.

--Rich

 

[TRDejaVu]

After getting the car out of the barn, I completely replaced all the brake and clutch lines and changed all seals (including splitting the calipers). I say that as I wasn't able to just do a flush and changeover. I can't compare clutch pedal feel to original fluid as my previous TR drive was about 26 years earlier.

I have put about 3,500 miles on this car with Silicone and no issues in the clutch or brakes that I have noticed.

 

[angelfj1]

Last night I finished the change-over to silicone hydraulic fluid. I finished the brakes at midnight. More on them in a moment. Earlier in the evening I worked on the clutch system – and here is the rest of the story. I was on a business trip this week but managed to get parts placed on order with two of the “big three” LBC suppliers. Considering the trouble I had had with the clutch bleeding process last week, I decided to order a new master, slave, hydraulic hose and SS line. My theory was that all of the components would be new and no single “old” part would jeopardize the reliability of the system. It was necessary to place orders with two suppliers. My preferred supplier did not have the master or slave or hose. They did have the SS line and some other less critical bits I needed. Back-up supplier did have master slave and hose. So between the two suppliers , I had everything covered. I got home about 5pm after traveling most of the day from the Northwest. I was tired but delighted to find two boxes from UPS. Upon opening them I found everything I needed to make the clutch work again and with silicone fluid. I removed the old slave, master, hydraulic hose and hard line and set them aside to be cleaned and inspected later.
I opened the box containing the slave cylinder. This part was wrapped in brown paper with what looked like Hindi writing. I examined the slave inside and out – not bad, they even remembered to use rubber grease on the seals – the drillings and threads for the line fitting and bleeder looked real nice – I chased the threads anyway and mounted the slave – I noticed that the orientation of the mounting ears were such that the line fitting and bleeder would be in nearly the same horizontal plane. This is not ideal. It is better to have the bleeder above the line to facilitate the removal of trapped air bubbles. I mounted the slave and turned my attention to the master – although I thought the casting was rough and ugly, it appeared to be OK – mounted this and moved on to the SS line. The line needed to adjusted quite a bit to get it lined up with the hole in the master – I did this very carefully and moved on to the union and hydraulic hose. The hose looked similar to the original. However, the ferules at each end of the hose where different and I did notice that the red plastic material was stiffer than the original. I proceed in maneuvering the hose into position from above being careful not to bend or kink the . . . . “what was that noise” , Oh you dirty no good $%$^&*!!!!!! I don't believe it - :madder:

<span style="font-weight: bold">PIECE OF CRAP HYDRAULIC HOSE</span>

Now, I want everyone to realize that I did not abuse this hose. I needed to bend it slightly so get the threads started on the union (which connects the hose to the SS line) So fortunately the original hose was OK, and I got this part of the job finished. I ended up with a very good firm clutch pedal. But Tuesday morning, I will be making a call and burning someone a new bung. I am really disgusted and tired of the absolute crap that is being supplied. Even if this hose had not broken at the ferule ( and I am grateful it did) it might have AFTER it was installed. Then what? No clutch?
I knew something was wrong when I noticed just how stiff that plastic was - not really flexible. There has to be a better option.

Brakes - I did manage to get the brakes bled but I am not satisfied with the feel of the pedal. Each time I step on the brakes now, I have to pump them a bit to get a firm pedal. Does this mean that there is a leak somewhere? I don't see one. Will this situation improve as trapped air leaves the system or must I continue to re-bleed these bloody brakes?

 

[angelfj1]

Ian Why didn't you come over to help last night? I am sure you could hear my screams from your house!

 

[TR4nut]

Frank-

No doubt about, that line is garbage. Made to look somewhat like the original but it seems to me they used completely the wrong polymer system or something. I thought the original was made out of nylon, I remember them being very tough, I'm not sure you could break one if you tried. Vendor should pull the product.

Randy