BMW Luxury Touring Community banner

1 - 10 of 10 Posts

·
Old Slow Guy in A Fast Car
Joined
·
8,601 Posts
Discussion Starter #1
As some of you know I had a rear brake line failure last week. :eek: With help from the "ALL KNOWING" folks here (thanks Grif) I ordered the Spiegler line kit. Now what type of break fluid do y'all use? At my 24k service I change to all synthetic fluids including the brake fluid (Valvoline full syn) Should I stay with that or flush it out and go back to regular dot 4 ?
 

·
Premium Member
Joined
·
1,178 Posts
Steve,
was the synthetic Dot 4 or Dot 5? If Dot 5 I would be concerned about seal compatability on your calipers and master cylinders.

I believe we were looking at doing some prototype work for a company specifying Dot 5 and the seals were a very specific material. I will see if i can dig up any further info and post accordingly.

You want to try and do search on the Dot 5 to see if there is any mention of this.

Roy
 

·
Old Slow Guy in A Fast Car
Joined
·
8,601 Posts
Discussion Starter #3
bigbear said:
Steve,
was the synthetic Dot 4 or Dot 5? If Dot 5 I would be concerned about seal compatability on your calipers and master cylinders.

I believe we were looking at doing some prototype work for a company specifying Dot 5 and the seals were a very specific material. I will see if i can dig up any further info and post accordingly.

You want to try and do search on the Dot 5 to see if there is any mention of this.

Roy
On the bottle it does not say "DOT 5" just fully compatable with Dot3 and Dot4 brake fluids.
 

·
Premium Member
Joined
·
1,178 Posts
Steve,
If it says it is fully compatible with Dot 3 & 4 it should in theory work. I am going to attempt to attach a link to the MOA site tha discusses dot 3 -5 issues.

http://www.bmwmoa.org/forum/showthread.php?t=1878

I was mistaken on the prototype hear at work. It was a silicon based fluid and not Dot 5.

Roy
 

·
Old Slow Guy in A Fast Car
Joined
·
8,601 Posts
Discussion Starter #5
bigbear said:
Steve,
If it says it is fully compatible with Dot 3 & 4 it should in theory work. I am going to attempt to attach a link to the MOA site tha discusses dot 3 -5 issues.

http://www.bmwmoa.org/forum/showthread.php?t=1878

I was mistaken on the prototype hear at work. It was a silicon based fluid and not Dot 5.

Roy
Thanks Roy !!!! I will check my bottle again tonight But.... I don't remember seeing anything about Dot5 or "Silicone" on the bottle. My only concern is the "Synthetic" part now. If I go back to "Regular" dot4 I should be OK.
In looking at the seals in the old master cylinder they where NOT swelled just one was torn. Also the rubber gasket in both frt & rear master cyl look good no swelling there .
 

·
Premium Member
Joined
·
1,178 Posts
Steve,
I did some research on the Valvoline Syntec and their website states that their Dot 3/4 is fully compatible with conventional Dot 3 & 4 fluids. The added advantage of the Synthetic is higher heat capabilities. That may be a consideration depending on your riding style. Don't recall if there was any mention of less susceptibility to moisture.

Roy
 

·
Wrencher Extraordinaire
Joined
·
13,775 Posts
Your safe Steve. I use the Valvoline full synthetic brake fluid on all my flushes.
 

·
Old Slow Guy in A Fast Car
Joined
·
8,601 Posts
Discussion Starter #10
dang i love this site and the "ALL KNOWING" folks that live here ;)
I have shipping confirmation on my new Spiegler SS line kit .It will be here Friday. Now the real fun begins the full tear down to replace ALL the rubber lines.Thanks everyone for the advice, Maybe when I grow up I'll be as smart as y'all :rolleyes:
 
1 - 10 of 10 Posts
Top