The fluid level float came apart in my brake reservoir. What are you guys using now that they seem to be discontinued? I have a 2002 parts car I can steal one from if I have to.
#6 in diagram
#6 in diagram
Brake fluid reservoir float?
- Thread starter dang
- Start date
Used is the only solution
If you will use white.... $11.50
Brake Fluid Reservoir Cap with Warning Switch
Brake Fluid Reservoir Cap with Warning Switch
$34.45
$11.50
Quantity:
Part Number: 34321153156
Quantity needed: 1Manufacturer: ATE (OEM)
Quantity in stock: 16Ships today
Search results for part number: '390427'
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Brake Fluid Reservoir Cap with Warning Switch
Brake Fluid Reservoir Cap with Warning Switch
$34.45
$11.50
Quantity:
Part Number: 34321153156
Too bad the float is not interchangeable with the black cap style. I forget not everyone needs original. 
This could work
www.bts-autoteile.de
Sieb mit Schwimmer
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Look closely- original has a screen (sieb) and an independent float (schwimmer) with a rubber connector and a black lid with a blue electrical cap.
the rm European one is white and a complete unit
the one from Joachim is for the part that goes bad- no cap
the rm European one is white and a complete unit
the one from Joachim is for the part that goes bad- no cap
Don,
I know the original is completely different. However, there are 2 aftermarket ATE caps w/ floats. I have the 34321153157 in my E9 and it works. I was just curious how the 34321153156 is different other than the pn and price. Thx, Dan
Great question- there are half a dozen different ATE caps out there in white with different part numbers and prices. i finally just just went with the cheapest that worked! Blue I put in restorations and white in resto-mods.
as far as I can tell- just price and part number as you mention.
70% difference in price is huge to me.
Honolulu
Well-Known Member
When I swapped in the 5-speed that replaced the 4-speed that replaced the auto trans, I found I'd used a 2002 part from my stash. Different: works.
Same reservoir
tochi
Well-Known Member
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Brake reservoir float musings:
Decomposition of a simple press-fit rubber grommet or seal is the problem source. The rubber bit that sits or is cradled in the top of the reservoir float also serves to attach the float to a brass rod that is responsible for creating a simple electrical circuit. When the rubber seal perishes this allows detachment of the brass rod from the float. So, resolution seems to be replacement of the rubber grommet/seal or an alternate means of attaching the brass rod to the float - without damaging the integrity of the float.
A dab of epoxy would seem to be the perfect rubber replacement; however, I would be concerned about the epoxy’s compatibility with constant brake fluid immersion. Same concern with other adhesives, urethanes, silicone RTV etc. I once found a donor float assembly that had the float and brass rod connected with what appeared to be hardened Permatex. The result was not pretty but it evidently worked. I did not use this example, but gave it to someone else. Another approach might be to find a viton o-ring or similar. I found such a plug in an extra parts drawer, but was concerned that the fix would be short-lived, not knowing how the rubber might react with brake fluid. Another somewhat inelegant fix might involve using some (brake-fluid-compatible) plastic from another brake fluid reservoir assembly. Using a heat gun, the plastic could be melted and formed to take the place of the perished rubber.
FWIW, I ended up using a new old stock float assembly with the understanding that it will not last indefinitely.
Decomposition of a simple press-fit rubber grommet or seal is the problem source. The rubber bit that sits or is cradled in the top of the reservoir float also serves to attach the float to a brass rod that is responsible for creating a simple electrical circuit. When the rubber seal perishes this allows detachment of the brass rod from the float. So, resolution seems to be replacement of the rubber grommet/seal or an alternate means of attaching the brass rod to the float - without damaging the integrity of the float.
A dab of epoxy would seem to be the perfect rubber replacement; however, I would be concerned about the epoxy’s compatibility with constant brake fluid immersion. Same concern with other adhesives, urethanes, silicone RTV etc. I once found a donor float assembly that had the float and brass rod connected with what appeared to be hardened Permatex. The result was not pretty but it evidently worked. I did not use this example, but gave it to someone else. Another approach might be to find a viton o-ring or similar. I found such a plug in an extra parts drawer, but was concerned that the fix would be short-lived, not knowing how the rubber might react with brake fluid. Another somewhat inelegant fix might involve using some (brake-fluid-compatible) plastic from another brake fluid reservoir assembly. Using a heat gun, the plastic could be melted and formed to take the place of the perished rubber.
FWIW, I ended up using a new old stock float assembly with the understanding that it will not last indefinitely.
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More prevalent is the float filling with brake fluid.
tochi
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I do not doubt that plastic floats fail. I just do not specifically recall experiencing this situation. As I mention above, I have experienced the brake warning light and discovered that the float was detached. A few donor float assemblies were likewise unusable because the rubber float attachment point was sloppy or severely decomposed making reattachment temporary and futile.
I would imagine that a plastic float could be repaired and resealed, but ensuring that the float is dry/empty before permanently resealing, especially in the case of a pinhole leak, would be daunting and ordinarily not worth the effort. To be clear, replacement with a new part seems most prudent, but occasionally, there may be alternatives. I hasten to add that I have seen numerous brass carburetor floats that have been kept in service by re-soldering. Plastic, not so much.
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I’ve had the disintegrating rubber issue, it gets nasty
I have had both failures.
Vintage56
Active Member
Would using thin small-sized metal parts from a rivet of the same size of the perished rubber work or create a short in the connection? I will assume that the metal will last indefinitely and as long as it doesn't break the circuit...Thoughts?Brake reservoir float musings:
Decomposition of a simple press-fit rubber grommet or seal is the problem source. The rubber bit that sits or is cradled in the top of the reservoir float also serves to attach the float to a brass rod that is responsible for creating a simple electrical circuit. When the rubber seal perishes this allows detachment of the brass rod from the float. So, resolution seems to be replacement of the rubber grommet/seal or an alternate means of attaching the brass rod to the float - without damaging the integrity of the float.
A dab of epoxy would seem to be the perfect rubber replacement; however, I would be concerned about the epoxy’s compatibility with constant brake fluid immersion. Same concern with other adhesives, urethanes, silicone RTV etc. I once found a donor float assembly that had the float and brass rod connected with what appeared to be hardened Permatex. The result was not pretty but it evidently worked. I did not use this example, but gave it to someone else. Another approach might be to find a viton o-ring or similar. I found such a plug in an extra parts drawer, but was concerned that the fix would be short-lived, not knowing how the rubber might react with brake fluid. Another somewhat inelegant fix might involve using some (brake-fluid-compatible) plastic from another brake fluid reservoir assembly. Using a heat gun, the plastic could be melted and formed to take the place of the perished rubber.
FWIW, I ended up using a new old stock float assembly with the understanding that it will not last indefinitely.
View attachment 142219
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tochi
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The brake fluid reservoir “circuit” is completed at the cap floating “button” or “contact” - not unlike the carbon contact found in distributor caps. So, it is very unlikely for a metal rivet/washer that does not contact the cap “button” to interfere with or short the circuit.
Use of a rivet or part thereof as a workaround “may” work, but it is difficult to visualize how the rivet will attach to the plastic float. When new, the rubber bit fits snugly into the float and grips both the telescoping assembly (metal rod/plastic tube) and the float. Anything other than a snug friction fit may likely compromise the float’s integrity. Using some means of welding additional plastic to the float might work, but the few floats I have examined are fragile and do not appear to take well to heat. Also, if epoxy or other adhesives are used, any such substance needs to be compatible/resistant to constant immersion in brake fluid. Similarly, your proposed metal rivet part would need to be inert or have long term compatibility with brake fluid - or risk fluid contamination.
Use of a rivet or part thereof as a workaround “may” work, but it is difficult to visualize how the rivet will attach to the plastic float. When new, the rubber bit fits snugly into the float and grips both the telescoping assembly (metal rod/plastic tube) and the float. Anything other than a snug friction fit may likely compromise the float’s integrity. Using some means of welding additional plastic to the float might work, but the few floats I have examined are fragile and do not appear to take well to heat. Also, if epoxy or other adhesives are used, any such substance needs to be compatible/resistant to constant immersion in brake fluid. Similarly, your proposed metal rivet part would need to be inert or have long term compatibility with brake fluid - or risk fluid contamination.
Vintage56
Active Member
Here's what I created using the original pieces except for the rubber piece that had disintegrated (it's shown near the paper towel in photo #5). I used JB Weld to seat a small rivet and a small washer into the float. Then I inserted the brass rod to go through the strainer as original and slipped the plastic spacer onto the rod per original so that I then had photo #3. Photos #4 & #5 show the completed assembly. The brass rod was also seated into the JB Weld so it ain't ever going anywhere. I let this sit overnight for 24 hours.
Per the packaging, JB weld uses a metal and epoxy-like compound that when mixed together will not be damaged by brake fluid or other caustic chemicals. In 24 hours, the assembly was dry and ready for service. It works perfectly. Light out. Hand brake release shuts the red dash light off.
Per the packaging, JB weld uses a metal and epoxy-like compound that when mixed together will not be damaged by brake fluid or other caustic chemicals. In 24 hours, the assembly was dry and ready for service. It works perfectly. Light out. Hand brake release shuts the red dash light off.
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Vintage56
Active Member
Oh, by the way, the rivet and the washer are made of aluminum. I took it from an assortment of rivets that I had of various sizes to reconnect riveted parts.